Appendix E E Appendix 2015 Ten Year Statement Electricity Technology Appendix E 1 2 5 7 41 12 15 19 31 21 37 28 52 26 23 59 62 49 55 45 33 80 64 66 ...... Appendix E Electricity Statement Year Ten 2015 E2 – Underground cables for power transmission...... E3 – Onshore cable installation and landfall ...... Switchgear – E4 E1 – OverheadE1 lines Thetransmission different many network of made is types.equipment different the Descriptions of equipment, its capabilities, usage, and limitations are presented here. development for expectations Contents E5 – Transformers E6 – Shunt reactors E7 – Shunt capacitor banks E8 – Static compensators VAR (SVC) ...... E9 – Static compensator ...... (STATCOM) – SeriesE10 compensation ...... – QuadratureE11 boosters & seriesreactors ...... – SubmarineE12 three core cables – SubseaE14 cable installation & DC AC ...... – OffshoreE15 substation platforms...... – HVDC: currentE16 source converters ...... – HVDC: voltageE17 source converters ...... – HVDC: extrudedE18 cables ...... – HVDC: submarineE19 mass impregnated cables E20– HVDC: overhead lines...... E21 – HVDC: switchgear ...... optioneering strategic offshore for availability Technology – E22 E23 – Unit costs ...... E13 – SubmarineE13 single core cables Appendix E OHL maintenance E1.1 Figure trade-offs. environmental and civil mechanical, performance electrical and security, costs to betransported, energy between balance a using overhead designed lines are insulating medium, main the as air With users. power bulk electricity and companies distribution solution for power between connections stations, default the preferred as companies transmission by lines (OHLs) used Overhead electricity are 2015 Ten Year Statement Electricity Overhead linesOverhead E1Appendix – 2 Appendix E 3 . .
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. 2 . . For new infrastructure, . Although existing lines are are lines existing Although . . . This change has led a review to is a possibility in close proximity to the line the to proximity possibility close a in is Dependencies and impacts and Dependencies for criticised sometimes are lines Overhead view the spoiling generally accepted as a necessity with a clear benefit, the construction of any new significant infrastructureis often an emotive issue The size and impact of transmission voltage OHLs are often of particular concern some to public the of members Depending on voltage, phase configuration and noise audible some bundle, conductor potentially is circuits OHLs of installation The cables, of installation the than disruptive less the of nature linear continuous the where construction at ground level can require road closures and diversions for significant periods. for consent planning achieving However, challenging more be can routes line overhead Availability OHL isHVAC a mature technology with many to up components offering reliable suppliers 400kV, which is the maximum voltage used in the UK and technologies manufacturing in Advances materials mean that designs that were not uneconomic were or achievable practically now have new potential visual amenity can be a key driver in the design of more traditional designs and the the and designs traditional more of T-pylon Grid National the of development which has been proposed for use on the the on use for proposed been has which project Hinkley-Seabank com/ .
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. .
. The
ribapylondesign The . . . . . 04mm diameter .
. . Examples include those Examples those include . . Standard conductor sizes . Shorter towers mean shorter 7 to 41 7 to . The conductor insulation is provided provided is insulation conductor The Decisions on tower type and tower on Decisions . . RIBA Pylon Design Competition http://www Competition Design Pylon RIBA T-pylon offered for first time http://www.nationalgridt-talk.com/ maximum rating for a single circuit with a triple conductor bundle is 3820MVA 1 2 The route design musttry strike to a balance between the size and physical presence of structures used per pylons more in resulting lengths, span kilometre In the UK, OHL designs must comply standards and regulations statutory with An OHL route consists of one or more towers by suspended conductors conductors are connected the to towers made traditionally are which insulators, with using cast iron caps encapsulating glass or porcelain beto the most cost-effective method of transmission HVAC The towers are designed support to a variety loads structural of imposed weather by events such as wind conductor additional the with along ice, and tensions caused changes by in route to transition or termination line direction, cable underground size are based on capability, visual and considerations economic Electricity Statement Year Ten 2015 so OHLs air, by are generally considered These include safety requirements such requirements These safety include electromagnetic clearance, ground as fields, earthing, safety signs and preventing climbing unauthorised Capabilities The UK introduced OHLs in the 1920s The current transmission system can carry through electricity of quantities greater far increasedvoltages and the capacity carry to conductors advanced more and larger Transmission OHLs in the UK are operated at voltages ranging from 400kV to 275kV Most routes have two circuits each, with three phases per circuit range from 24 Appendix E design traditional the over benefits of anumber offers polymer rods bonded to silicon rubber housing reinforced glass-fibre from made products A new generation of composite insulator length of insulator unit linking individual ‘sheds’ to form the required and porcelain, with ‘cap and pin’ construction The traditional insulation materials are glass T-pylon E1.2 Figure 2015 Ten Year Statement Electricity and take less time to install time less take and products, which are easier to handle performance, reduced cost and lighter . These include enhanced electrical include These electrical enhanced Overhead linesOverhead E1Appendix – .
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on the transmission system in the future deployed be may that products of number existing lines to rebuild need the avoiding thereby structures, ofpossibility increased ratings using existing on transmission systems deployment for market to the offered being sag (HTLS) composite cored conductors is A new generation of high temperature low . National Grid is reviewing a . HTLS offers the .
4 Appendix E 5
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They are also used at locations where, where, locations at used also are They . Underground cables are used in built-up and built-up in used cables are Underground space where areas urban populated densely extremely is infrastructure above-ground for limited measures, mitigation visual or landscape for considered be may cost additional their and parks national as such appropriate, beauty natural outstanding of areas
. . cables for power transmission power for cables Appendix E2Appendix – Underground Unlike overhead lines, underground cables underground lines, overhead Unlike medium insulating an as air use cannot Figure E2.1 Figure Transmission cables installed in a 4m tunnel So they need provide to their own insulation adding length, entire the along materials significantlyto the cost. Air is also better at transferring heat away from conductors than conductors larger so soil, and insulation cable are usually required in order transmit to the same power levels as OHLs Underground cables are electricity used by transmission and distribution companies across cables (OHLs), lines Along overhead the with world. stations the connectionsprovide and between power voltages electricity usersbulk and lower at power somein countries connections provide between centresdistribution and end the consumer. Electricity Statement Year Ten 2015 Appendix E at a depth of around 1m in flat agricultural land. 1magricultural flat in around of adepth at increased ratings Larger conductors and higher voltages mean the installation method and soil resistivity as well as conductors of size and number transmission cable system depends on the a of rating or capability power-carrying The crosses it land of sections the all of must obtain easements from the land owners For direct buried underground cables, utilities control network voltage of additional reactive compensation to help used in AC systems may require the installation where and capacitive inherently are Cables 2015 Ten Year Statement Electricity 1 conductor size and circuit length increases with cable operating voltage, needed for a particular transmission route additional reactive compensation will be required but also increases the level of cable insulation voltage allows more power to be transmitted 132kV from to 400kV ranging Transmission cables are operated at voltages for the reactive compensation plant compounds to build required be will space land have one or two conductors per circuit per conductors two or one have used for DC cable systems too systems cable DC for used cable systems HVDC into introduced being now are that (PPL) have also used polypropylene paper layers oils to extruded plastic insulations paper insulation using low pressurised viscosity construction with a hollow conductor and (SCFF) fluid-filled self-contained from Transmission cable insulation has developed coating plastic protective a and sheath layer, alead insulation an conductor, a copper of consist cables At 400kV and 275kV, transmission Capabilities OHL circuits, large will cables very be required high-capacity of ratings the to match order HITACHI, The 1,400-MW Kii-Channel HVDC System (online) System HVDC Kii-Channel 1,400-MW The HITACHI, Available: http://www.hitachi.com/ICSFiles/afieldfile/2004/06/08/r2001_03_111.pdf . At 275kV most and 400kV circuits cables for power transmission –Underground Appendix E2 . SCFF technology has been . Cables are usually buried . The likelihood that . Increasing the the .Increasing . 1 . Additional . SCFF cables .
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In .In .
. (Accessed: 9 September 2015) 9September .(Accessed: them (the swathe) (the them to install required land the of width the does so increases, circuit per cables of number the As issues around the disturbance of land of disturbance the around issues systems do still encounter some environmental Cable periods. significant for diversions and closures road require can level ground at the continuous linear nature of the construction installation of OHL circuits the than disruptive more potentially is systems The installation of underground cable audible noise less generate they because OHL than issues are generally less prone to environmental OHL of sections between ends system above ground, especially at the terminal are still considerable portions of the cable there OHL than amenity visual on impact alower have systems cable Although Dependencies and impacts increased significantly. have systems cable (XLPE) extruded of cables have been manufactured, while sales SCFF fewer far mid-nineties, the Since specialised, with proportionally fewer suppliers The higher-transmission voltages are more manufacturers reliable offering products many with mature is technology cable HV Availability seasons other in are they than winter in higher conductor the of and the safe maximum operating temperature Ratings are calculated on ambient conditions trench each in conductors of number and size the on based 240MVA to 3500MVA from range can circuit each for rating the 400kV At 275kV and supplier information sheets in quoted widths corridor to most added be to needs maintenance for allowance A 3m 400kV routes high-capacity for required be may 50m as . . .
Consequently, ratings are are ratings .Consequently, Cable swathes as wide wide as swathes .Cable .
. This is because This is because .
Cable systems systems .Cable .
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. 6 . Appendix E 7 Appendix E3 – Onshore E3 Appendix cable landfall and installation Figure E3.1 HDD rig (Image courtesy of Land and Marine) Onshore HVDC and HVAC cables can be direct buriedOnshoreHVDC and HVAC trenches,in installed or ducts dedicated pipes or in in cable latter (the tunnels is very and option expensive normally reserved urban for only areas where space trenches is unavailable). excavate to Electricity Statement Year Ten 2015 Appendix E A typical open trench cable swathe cable trench open A typical E3.2 Figure 1m cover 1m Direct buried cables have approximately 2015 Ten Year Statement Electricity 2 1 public general the and cables the for protection adequate to ensure essential are design pairs in the same trench same the in pairs DC cables are generally installed in bipole material in the case of agricultural land) covered in engineered materials (or indigenous then resistivity, thermal to improve (CBS) sands heating causes a slight reduction in rating) mutual trefoil in cables the of proximity close more compact trefoil formation (although the the in or flat laid be can cables Transmission National Grid, Undergrounding high-voltage electricity transmission – the technical issues (online) UndergroundingTheTechnicalIssues3 Available: http://www CIGRÉ TB 194 “Construction, laying and installation techniques for extruded and Self contained fluid filled cable systems. cable filled fluid contained Self and extruded for techniques installation and laying 194 “Construction, TB CIGRÉ . Cables are buried in cement-bound 1 but detailed site survey and system system and survey site detailed but installation and landfall cable Appendix E3 –Onshore . nationalgrid . . com/NR/rdonlyres/28B3AD3F-7821-42C2-AAC9-ED4C2A799929/36546/ . pdf 1 .
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boring and cased auger boring are other methods available, such as auger horizontal directional drilling (HDD), but there using crossed be can areas sensitive other and rivers railways, roads, as such Obstacles is required for inspections access and activities jointing cable for needed cables the from transfer heat to improve order in sealed and Bentonite with filled be can Ducts lengths. in through pulled be then can cable the and delivery cable of advance in installed be can ducts or Pipes . (Accessed: 9 September 2015) . Jointing pits are are pits .Jointing . 2 . 8
Appendix E 9 . a beach area may also be viable, but HDD is seen as less intrusive, offers betterprotection cableto systems and, when correctly executed, damage environmental minimum causes Trenching and ploughing through through ploughing and Trenching . Figure E3.3 Cable plough on shore (image courtesy of IHC Engineering Business) The shoreline transition on submarine cable submarine on transition shoreline The projects – also known as landfall – is typically directional with HDD, through out carried the from rig boring steerable a using boring side onshore Electricity Statement Year Ten 2015 Appendix E Data extracted for onshore cables onshore for extracted Data E3.1 Table 3 load abnormal an as qualifying this above anything with load), and (vehicle tonnes 44 is weightmaximum permissible on British roads –the basis aproject on considered to be Transport height/weight restrictions will have drum. steel onto a fitted be can that amount to 100 tonnes) up capacity (carrying lorry alow-loading on site to the transported be can drums Larger requires specialist knowledge making landfall is a complex operation that atrench, via or by HDD prepared a duct various tasks support the for team adiving with along required, is (MPMV) vessel marine amulti-purpose and/or duct the through cable offshore the to pull used is awinch and A transition joint pit is constructed onshore cable offshore the for aconduit to provide used are ducts or pipes protector and size required to the out reamed is hole pilot The seabed the 15m of below depths and to 500m up of distances horizontal typical with to sea, out and defences sea under pass can HDD 2015 Ten Year Statement Electricity 5 4 (Steel) Third-Party Damage to Underground and Submarine Cables, December 2009 CIGRÉ Working Group B1 Department of Transport: The Road Vehicles (Construction and Use) Regulations Available: https://library (rev guide User’s Systems Cable Land XLPE ABB, XLPE%20Land%20Cable%20Systems%202GM5007GB%20rev%205 Drum Drum St 40 St 36 St 30 Type installation and landfall cable Appendix E3 –Onshore Width Width Drum Drum 2400 2400 2400 mm Cable length is limited to the to the limited is length .Cable For the marine works a barge abarge works marine the .For . e . abb Diameter . 21, Technical Brochure TB 398, . Whether it is through Drum Drum 4100 3730 3130 mm . com/public/ab02245fb5b5ec41c12575c4004a76d0/ . Weight Drum 3500 2800 1700 3 kg .1) (online) 4 . .
Length of cable, for a specified cable diameter, diameter, cable aspecified for cable, of Length 3280 m 3120 m 1680 m 66 mm 66 . (Accessed: 9 September 2015) 9September .(Accessed:
of all underground cable failures cent 70 per around for accounts damage party have a similar availability to AC cables HVDC underground are cables expected to reinstatement for week one and drilling for weeks two preparation, site for needed be will greater than 500m than greater Directional drills are available for distances a particular drum size: drum a particular on transported be can that cable of length Table E3 drums steel on transported are cables Land boxes for sheath bonding and earthing trench(1) cable asingle for 5m least at of swathe to atotal jointing bays and construction access, leading for required width increased 1m with wide, 1-1 usually are trenches Cable cables insulated paper impregnated mass for days to five three and XLPE for joint per day one of range the in usually are but type, Onshore jointing times according vary to cable Capabilities cables have an expected lifetime of 40 years 40 of lifetime expected an have cables that can be carried on one drum one on carried be can that . pdf . 1 shows the continuous maximum 2180 m 2130 m 1210 m 76 mm 76 . .
AC cables also require link link require also .AC cables Typically at least one week week one least at .Typically .
1570 m 1330 m 92 mm 92 860 m . 5m deep and and deep 5m 5 Onshore .Onshore 116 mm 116 . Third- 850 m 890 m . – . .
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10
Appendix E
. 11 .
. 5km, .
There . . There 6 . This may mean . . Additional mobilisation costs costs mobilisation Additional . . roads, railways, and gas, electricity g . . Tidal conditions and weather can also also can weather and conditions Tidal . Vale of York 2 x 400kVVale of York circuits over 6 Lower Lea Valley power line undergrounding line power Valley Lea Lower West Byfleet undertrack crossing Gunfleet Sands landfallto Clacton substation project HVDC NorNed and per km costs also need be to considered by dictated largely are operations Landfall many because considerations environmental such designations have shoreline of areas as Sites of Special Scientific Interest(SSSI), Ramsar sites and Royal Society for Protection of Birds (RSPB) reserves that drilling can only take place at certain times gas oil, with resources, for competition is and other construction projects as well as significant market activity overseas. present often routing cable land Landfall and the most thermally limiting casefor cable rating examples Project n affect the operation of Multi Purpose Marine Purpose Multi of operation the affect Vehicles (MPMVs) and diving teams As such it may be economic use to larger a land and landfall the for cross-section cable route than for a submarine section, ensure to that thermal bottlenecks do not de-rate the entire cable system Generation and offshore transmission transmission offshore and Generation project and licence additional be also may management costs such too, as enabling the third services to belonging existing of crossing parties e licensees may have compulsory acquisition have licensees may compensation and legal are there and powers powers these with associated costs and water services When it comes laying to cables their bulk and joints between length total the limits weight additional the for made be must allowance So cost (and time) for civil engineering works, land access issues and the completion of cable activities jointing n n n
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However, However, .
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. . Thomas Worzyk, Submarine Power Cables: Design, Installation, Installation, Design, Cables: Power Submarine Worzyk, Thomas 978-3-642-01270-9 ISBN 2009 Published Aspects, Environmental Repair, 6 Availability prime are Sons & Durkin Neary Construction, cable HV underground of installers companies including Carillion, United Utilities United companies Carillion, including Cable and Line Overhead Grid’s National and Alliance Partners (AMEC, Babcock and experience extensive have all Beatty) Balfour capabilityand Major directional drilling providers with the the with providers drilling directional Major projects manage to capability and experience of this nature include AMS No-Dig, Land & Marine, Allen Watson DEME Ltd, , Stockton (parent VolkerInfra and 500m+) (HDD Drilling company Visser & Smit Hanab) Electricity Statement Year Ten 2015 Belgian-based DEME has group companies group has DEME Belgian-based experience GeoSea with and Tideway including operations landfall of impacts and Dependencies cable process, planning project the Early in route surveys are required determine to the the for option routing cable feasible most cable system and also determine to first pass cable route lengths for budget purposes Geotechnical surveys are also required at this the along conditions ground determine to time route so as establish to where more expensive required be may methods installation public along routed be potentially can Cables potentially for need the avoiding highways, costly wayleaves and access agreements (including cross-country go routes cable If access for HDD), additional costs consider to include wayleaves, access agreements, trackway costs, farm drain repair, soil charges damage crop and reconditioning Cable system design is an essential elementof any cable project and may have a considerable impact on the final costs. are rock through drilling and Trenching considerably more expensive and time ground softer through than consuming Appendix E (image courtesy of Siemens) of courtesy (image 420kV) to (up GIS E4.1 Figure enclosure. metallic earthed withinencapsulated an closely integrated fully components and GIS are in air. connected byand busbars open Conversely discrete components of typically equipment AIS are The transformers. switches instrument and earthing disconnectors, including breakers, equipment circuit (GIS). switchgear term The of covers avariety switchgear switchgear gas-insulated (AIS) and air-insulated types: main two are There the network. to in order control powerto flows beperformed on allows that switching equipment is Switchgear 2015 Ten Year Statement Electricity Switchgear E4Appendix –
Typical 132kV AIS bay 132kV AIS Typical E4.2 Figure
12 Appendix E 13
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63 420 1425 . Older Up to 5000 1 below . The remaining remaining The . 40 300 3150 1050 . . . AIS equipment is commonly used is equipment AIS . Modern AIScircuit breakers typically 40 . 650 145 2000 as an arc-quenching medium and are are and medium arc-quenching an as 6 allowsthe switchgear be to more compact, relevant data technical switchgear Typical which is why GIS is typically installed in cities cities in typically installed is GIS why is which and offshore locations where space is at a premium in more rural and spacious areas, such as brownfield sites. Capabilities voltages rated in available is Switchgear up 1200kV to with rated normal currents of up 8000A to for UK use is detailed E4 in Table maintenance requirements principally concern concern principally requirements maintenance operating their and devices switching the lubrication and inspection with mechanisms, intervals of many years maintained be to needs AIS Modern conducting the because frequently more local their to exposed are components environment – and disconnector and earth switches have maintenance intervals of only a few years use SF may reduce the need for on-site attendance inspections and checks for switchgear typically requires more frequent frequent more requires typically switchgear operating their because mainly maintenance, because and complex more are mechanisms they show signs of wear due their to age very similar their to GIS counterparts
25 36 170
2500
. ) at a pressure 6 . . . The insulating gas 1 . For certain applications, certain applications, For . The insulating gas also also gas insulating The Remote condition monitoring monitoring condition Remote . . Rated voltage kV Other devices like disconnectors and disconnectors devices like Other . Rated normal current, A Rated normal current, Rated short-circuit breaking breaking Rated short-circuit kA current, Rated lightning impulse withstand IEC 62271-203 ‘High-voltage switchgear and controlgear – – controlgear and switchgear ‘High-voltage 62271-203 IEC Part 203: Gas-insulated metal enclosed switchgear for rated voltages above 52kV’ of a few bars, which has excellent insulating solution compact more a allows and properties beto achieved than is the case with AIS Compact GIS solutions up 400kV to can have a complete bay delivered, fully assembled and tested, on the back of lorry a One of the main benefits of enclosing equipment is protection against harsh environments The present generation of GIS requires little maintenance earth switches can also have special duties duties special have also can earth switches them with associated such as capacitor banks and shunt reactors, additional duty-specifictesting may also be required systems for things like electronic gas density Availability CG Grid, Alstom ABB, include Suppliers Ormazabal,Power, Hapam, Hyosung, Hyundai, Siemens and Mitsubishi impacts and Dependencies As well as switching load currents and fault currents, circuit breakers should bespecified beto capable of breaking the capacitive cables with associated currents charging lines overhead and 1 Table E4.1 Table GIS is defined ‘metal-enclosedas switchgear least at obtained, is insulation the which in in part, an by insulating gas other than air at atmospheric pressure’ Electricity Statement Year Ten 2015 in GIS is sulphur hexafluoride (SF Appendix E with SF with filled equipment of repair and Maintenance apremium at is space where GIS costly to install need the reduce devices these substations, AIS of footprint physical the along with other hybrid switchgear to become available at transmission levels, starting is devices separate several of functions the combines that switchgear AIS New 2015 Ten Year Statement Electricity 4 3 2 by suitably trained and qualified personnel. personnel. qualified and trained by suitably Ref Ref CIGRÉ WG A3 WG CIGRÉ CIGRÉ WG hexafluoride’. 23 sulphur of handling and Use 303: –Part controlgear and switchgear ‘High-voltage 62271-303 IEC/TR 150, February 2000 .150, February 509, 513 2012 514, .509, and 21 October 6 may require the gas to be removed removed to be gas the require may Switchgear E4Appendix – . . 02, ‘Report on the second international survey on high voltage gas insulated substations experience’, service 06 ‘Final Report of the 2004 – 2007 International Enquiry on Reliability of High Voltage Equipment’, Equipment’, Voltage High of Reliability on Enquiry International – 2007 2004 the of Report ‘Final 06 . . . . By reducing
published by CIGRÉ Data on GIS service experience has been SF toxic decomposition products – guidance on and reactive highly to yield gas decomposed cause can fault) internal an of aresult as or (such as arcing during circuit breaker operation atmosphere to the deliberately released be not should and The gas has a high global warming potential 6 gas handling is given in . Exposure to high temperatures temperatures to high Exposure . 3, 4 3, . 2
14 Appendix E 15
Appendix – E5 Transformers Figure E5.1 Transformers are used where differentTransformers operating as transforming interface. need As the well to voltages also impedance introduce between thethey voltage, currents fault controlling levels. safe systems, to Electricity Statement Year Ten 2015 Appendix E distance power transmission long efficient for required voltages high to the up the wind turbine array collection voltage to step used is this offshore network; to the Step-up transformers connect generation to regulate the voltage within design limits (OLTC) changers tap load on with equipped losses) or transport cooling, noise, (size, constraints design on different construction options depending cooling for oil in immersed core iron alaminated around wrapped Transformers are copper windings typically levels for distribution voltage from transmission to more manageable the down to step used are transformers supply conductors the in losses power reduces required conductor the of cost the and size the reduces flow,which power same the voltage reduces the current required to give E5.1 Table 2015 Ten Year Statement Electricity Rated voltagekV Power (MVA) Impedance (%onrating) Cooling Insulation withstand(LIWLkV) Windings Losses (load/noload)% Weight –withoutoil(tonnes) Volume ofoil(litres) Transformers E5 – Appendix HV transformers can be be can transformers .HV . There are many many are .There . Increasing the It also also .It Grid .Grid .
400/132/13 1425/650 0 .39/003 180-240 90000 ONAF 15-20 Auto 200 to the offshore platform offshore to the 400V windings to provide supply the auxiliary with equipped transformer earthing a zig-zag transformer the of side voltage low the on earthing for provided array farm wind the current ratings and manage fault levels within available exceed to not and segregated be windings allowsecondary the switchgear to delta windings secondary high voltageprimary winding and double voltage array voltage to offshore network transmission farm wind offshore the up to step used are they since units generation as degree to some transformers shouldOffshore be considered Capabilities requirements. fixture hardware and painting the same as onshore units but have different largely are transformers power Offshore . Typical designs use a star connected 245/33/33 1050/170 0 .5/005 50000 ONAF 15-20 This is commonly done with with done commonly is .This Ydd 180 150 A neutral point must be be must point .Aneutral . . The double The double 145/33/33 120-180 0 .5/005 650/170 20000 ONAF 15-20 Ydd 90
16
Appendix E . 17
These . . Stainless
. . Associated radiators radiators Associated . . Standardisation of of Standardisation . . . As with all the equipment on the .
. Sea water-based cooling may . ratings, configurations and voltages across the minimise would farms offshore wind number of spares required for the apparent power which (MVA), comprises both the real power (MW) and reactive power reactive and turbines wind by provided (MVAr) power reactive as well as compensation cables of requirements platform, it is important that the paint is marine regularly, inspected and carefully applied grade, with defects taken care of promptly Transformer ratings will need be to specified voltages the to transformer winding generated vacuumby circuit breaker transients on the LV switching disconnector and windings could in time cause overvoltage damage due to part resonances winding In addition the to core and windings, a transformer cooling can have an OLTC, and maintenance, require which of all bushings, so important it’s monitor to all parts of the transformer The procurement lead time for a large power transformer is approximately months 24 to 18 and there is a wide range of worldwide manufacturers items heaviest the of one be will Transformers of plant on the platform and would normally be placed close theto centre of gravity, above the stability for jacket, or pile and cooling fans are placed on the outside of the platform oil/air conventional the to preferred be also based cooling steel hardware should be used where possible Dependencies and impacts and Dependencies design critical are space and Weight parameters for offshore platforms
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The . . . Autotransformers . The compact nature of of nature compact The . Generator transformers last last transformers Generator Offshore should units . Both autotransformers . . 1 . It also helps reduce any
. 25% are not unreasonable25% for supply . Guide on economics of transformer management: CIGRÉ technical brochure 248 brochure technical CIGRÉ management: transformer of economics on Guide be no less reliable than onshore, although although onshore, than reliable less no be the long cables used in offshore circuits may induce stressand resonance in the transformer energisation during the substation will result in close-up, very fast close-up, in result will substation the 1 are usually smaller and lighter than an transformer, power winding two equivalent between isolation electrical provide not do but the primary and secondary voltages or lower short circuit levels Transformers may be two winding, three winding or autotransformers have may transformers winding two and delta a with tertiary winding additional an harmonics triplen reduces which configuration, through passing harmonic) third of (multiples the transformer voltage unbalance between the phases the between unbalance voltage voltage of the tertiary winding may be chosen compensation reactive of connection allow to equipment at a lower voltage than the primary secondaryor windings The life expectancy of onshore and offshore transformers is determined the by loading, oil and paper generally is insulation the since Electricity Statement Year Ten 2015 This is discussed in the CIGRÉ technical brochureTB 248 Generator transformers are likely have to a shorter lifetime than supply transformers due loading heavier to Availability appropriately if reliable are Transformers specified and lookedFailure after. rates of 0 exhibit will units generation but transformers higher rates due heavier to usage (80-90% loading) around years, 25 while many supply units have been in service for 40 years or more Appendix E E5.2 Figure 2015 Ten Year Statement Electricity and dump tanks will be required separation bunds, Oil fire. transformer and spillage oil namely failure; amajor of event environmental risks on the platform in the greatest two the pose Transformers lifetime expectancy overloaded, although this decreases their service in still transformers the of ratings the within grid to the connected remain can farm wind maintenance or following a fault while the the transformers to be switched out for breakers section bus open normally with configured switchgear farm wind the have can transformer one platform offshore the on space of use efficient allows This switchgear insulated gas HV to the directly connected be can terminals HV Transformer n Additional information n n n n IEC 60076 – Power Transformers 60076 –Power IEC N A2-114, paper session CIGRÉ 2006 surveys, reliability Transformer 88_1, ELECTRA 1978.CIGRÉ Wind Farm, presented at 2008 Wind Integration Conference in Madrid, Spain Madrid, in Conference Integration Wind 2008 at presented Farm, Wind Offshore Nysted the of platform offshore the at failure transformer by a major transformers power large of service in failure on Survey International changers tap 60214IEC load –On . Andersen, J . Transformers may be temporarily Transformers E5 – Appendix Platforms with more than than more with .Platforms . . Marcussen, E This allows one of of one allows .This Aut o (star/star)
t r an . s Fire f or . Jacobsen, S m . er .
.
Two winding
t
(star/delta)
r an . s B f or . suppression or control should be investigated strength a bigger transformer due to lower dielectric need and oils mineral than expensive more are Synthetic oils are much less combustible but is recommended redundancy or overload options of analysis benefit acost so sourced, is mean extended outages while a replacement weather suitable and vessel arepair of and aspare of availability the on depending costly very be will offshore platform the from removal the replacement must be considered, particularly and failure atransformer around logistics The testedand successfully manufactured been has transformer 400kV filled ester synthetic first the and applications 400kV for esters synthetic of use the on Nielsen, Experience gained m er . (star/delta/delta) Research has been completed Three winding t r an s f or . m . er Long lead times could could times lead .Long .
.
An incident incident .An .
18 .
Appendix E 19
Appendix – E6 Shunt reactors Figure E6.1 Air core reactors (blue), (image courtesy of Enspec Power) Shunt reactorsShunt the for are compensate used to transmission AC in power reactive capacitive networks, regulating the network voltage. HVAC cables have a high capacitance a high and shunt cables have HVAC reactors are used onshore the interface at point; offshore the at platform substation and potentially alongpoints the cable intermediate at length as shore point). the at landing (such Electricity Statement Year Ten 2015 Appendix E Electricity Ten Year Statement 2015 Ten Year Statement Electricity similar to that of transformers of to that similar while oil unit immersed maintenance will be maintenance from apart visual inspection, the environment to exposure –and birds nesting as – such wildlife of impact the area, surface large to the due availability alower have will units cored changers) tap (without to transformers comparable are units immersed oil however reliability, reactor on data little is There Availability 250MVAr and to 800kV up available designs possible but generally regarded as special 100MVAr to 72kV up and available commonly are required, oil units immersed dominate are ratings high and limited is space where Generally, ACRs are cheaper but larger, so Capabilities protection and busbar via switchgear for operational switching HV to the connected or transformers power on reactors may be connected to windings tertiary effects saturation to core subject not are they cores, iron non-linear have not do they maintenance less need and reactors, core iron than simpler but larger are (ACR) reactors core to flow.Air current magnetising a higher for harder it makes core iron gapped the but similar construction to power transformers, a with oil of atank in immersed commonly design core iron gapped or core air an either have Reactors Oil immersed iron core reactors are are reactors core iron immersed .Oil Higher voltages and ratings are are ratings and voltages .Higher Shunt reactors Shunt E6 – Appendix . Iron core reactors are are reactors core .Iron . Air cored units need little . . Shunt .Shunt . Air .Air ACRs
As .As
during opening transient recovery voltage established (TRV) the particular in reactors, to switch tested and rated suitably to be need breakers Circuit fire. possibly and temperature can cause overheating, ageing ACR: excessive the in temperature the raise cables transmission offshore core three the and cables park power offshore the of demands reactive the to supply used with AC offshore transmission networks environment offshore the for the environment, making them better suited from protected well is reactor the and tank the beyond extending fields magnetic significant have not do atank in reactors immersed offshore problematic be could flow,which could currents circulating where in adjacent constructions must be avoided need specialised installation they so reactor the beyond extends field magnetic the that is ACRs with A drawback Dependencies and impacts manufacturers worldwide many are 12 there and to 24 months from range reactors shunt of times Lead n Additional information Reactors – Edition 1 –Edition 6: Reactors Part – transformers Power 60076-6 IEC . Note that harmonics can can harmonics that .Note . . Reactors can be be can .Reactors Metallic loops Iron core oil oil core .Iron . 0 (2007)
.
20 Appendix E . 21
. They can be open rack mounted
to achieveto the desired voltage and reactive power rating or, for lower voltage installations, fully enclosed fully installations, voltage lower for or,
Appendix – E7 banks Shunt capacitor Capacitor technology is used in SVCs, series and stations converter HVDC compensation, harmonic filters. The capacitor‘bank’ consists of connected capacitors in series and parallel Figure E7.1 capacitor bank National Grid 275kV Shunt capacitors control voltage. They provide reactive power to keep to power reactive provide They Electricity Statement Year Ten 2015 the voltage within operational within the voltage limits. Appendix E Electricity Ten Year Statement 2015 Ten Year Statement Electricity of service switching lumps of capacitance in and out dynamic variable response, rather than providing of capable is E9), which (Appendix STATCOM or E8) SVC (Appendix an as such oscillations requires a faster acting device An automatic response to faults and network reactors shunt and control changer voltage control devices such as transformer tap voltage control scheme, coordinated with other asubstation of part be can and control voltage state steady for used are banks capacitor Static future developments operational strategy, available footprint and any consideration into taking of capable be system needs to meet required is compensation reactive of Power system studies establish which type have individual banks (e banks individual have may 132kV at below and connected MSCs sections) STATCOM and SVCs (see management more need systems auxiliary and cooling their and expensive and out of service together service of out and in banks the of all switching of capable is that breaker circuit acommon via parallel in ganged breaker circuit own by their service of out and in switched being of capable n n n forms: several take can banks capacitor Shunt Capabilities n Additional information the power network (i network power the power electronic valves to connect them to use that (TSC) capacitors switched Thyristor them to the power network power to the them to connect breakers circuit dedicated use Mechanically switched capacitors (MSC) that LV,at i connected to the power network (usually Fixed capacitors that are permanently Capacitor Switching and its impact on power quality Electra No Electra . e . These technologies are more .11kV) Shunt capacitorShunt banks E7 – Appendix . 195, April 2001, WG 36 .195, CIGRÉ April The optimised solution must . . e . g . .SVC) 3 x 45MVAr), each each .3x45MVAr), . They may also be be also may .They . .
. 05/Cired 2 CC02, Thomas E Thomas 2CC02, 05/Cired around the world deployed 600MVAr and to 765kV up ratings requirement system by the determined is bank acapacitor of rating The Availability manufacturers worldwide many from available are These power reactive to accept ability its and location agiven at power reactive for requirement network’s power by the determined is and current, capacitive to switch ability breakers’ circuit by the limited is banks capacitor the of needed are breakers, circuit more with banks, smaller multiple required, is gradation finer If breaker. acircuit with units Capacitor banks are switched as lumped on some transmission systems needed be may facilities POW or network ganged together) (i breakers circuit by individual service of out and in switched are that capacitance of banks single comprise typically 275kV above at or system MSCs for connection on to the transmission the switching transients of amplitude the to reduce (MSC-DN) circuit MSC the on filter or (DN) network a damping transients generated switching any of amplitude the to reduce possible as crossing voltage zero to the near as closes breaker circuit the of pole each that to ensure facility control (POW) a point-on-wave require may MSC the for breakers circuit The and designing an MSC installation to be taken into consideration when locating on the connected power network, which need issues quality power and changes step voltage The switching of reactive power introduces Dependencies and impacts .
. e the individual banks are not not are banks individual .the . . . However, a damping . Other methods include . Grebe, .Grebe, There are units with with units are .There The overall size size overall .The .
.
22 . Appendix E 23
Appendix – E8 compensatorsStatic VAR (SVC) Figure E8.1 installation SVC Typical A static VAR compensator (SVC) is a power electronic a power is (SVC) compensator A static VAR application dynamically used to control the voltage operations.during or conditions switching fault Electricity Statement Year Ten 2015 Appendix E Code (STC) by the System Operator/Transmission Owner the onshore transmission system, as required of the offshore transmission network and point interface the at capability through ride fault provide SVC can rated A suitably Typical SVC configuration Figure E8.2 thyristor switched capacitors (TSC) and (TSR) reactors switched thyristor (TCR), combination of thyristor controlled reactors a using power reactive capacitive and The SVC function provides variable inductive system apower of parts different between damping where instabilities could arise methods different power electronic technologies and (STATCOMs) deliver a similar function using Essentially, SVCs and static compensators equipment of (FACTS) genre system transmission AC flexible the of part is It period. transient the during voltage the to support bystability rapidly supplying reactive power voltage to preserve designed SVC is The 2015 Ten Year Statement Electricity . SVCs also provide power oscillation Static VARStatic compensators E8 – Appendix . TC C R Tr omp
an s ens . These These f . o
r at me
o r r
.
TS
C square of the voltage the of square MVAr production reduces in proportion to the power, the reactive to provide AC components accordingly output MVAr its automatically control the voltage by changing to configured be or directly controlled be SVC may the of output MVAr power reactive TSCs and TSRs by the provided control reactive coarser the with TCRs, the variable reactive power response using continuously afast, provide SVC can An Capabilities winding tertiary transformer the via or transformer compensator a using AC network to the connected are so do not necessarily need an SVC an need necessarily not do so solutions can inherently control MVAr output, solution HVDC-based (CSC) converter source a current with or AC connections for used be SVCs can . Voltage source converter (VSC) HVDC Fi l t e Tr r . E an ar s t f hing o . r me r As the SVC uses SVC uses the .As The .The . 24 Appendix E 25
.
.
CIGRÉ, CIGRÉ, .
02, 1986 02,
. . . 01 . . . Mouatt, CIGRÉ, . . . Meisingset et al et Meisingset . . Janke, J M . . 02, 1995 01 . . . Cooling systems and control and CIGRÉ technical brochure TB093 – TB093 brochure technical CIGRÉ Guidelines for testing of thyristor valves for static compensators VAR WG14 Paris 2008 Static – TB025 brochure technical CIGRÉ Compensators,Var TF 38 B4_106 ViklandetB4_106 & Tunnsjodal – SVCs operating and execution project Design, experience Paris 2010 B4_201 Operational experiences of SVCs in Australia, A National Grid, UK: 60MVAr re-locatable re-locatable 60MVAr UK: Grid, National suppliedSVCs ABB by and Alstom Grid Brownwood, near Station switching Brown 345kV 2 x -265/+300MVAr, suppliedTexas: support the to Electric Mitsubishi by from energy renewable of transmission Texas west in sites generation Nysted Offshore Windfarm: -65/+80MVAr, -65/+80MVAr, Offshore Windfarm: Nysted onshore installed and supplied SVC 132kV Radsted)(at Siemens by comply to with requirements Code Grid Alleghny Black Power, Oak: 500MVAr, 500kV supplied SVC and installed ABB by reliability line transmission by improve to voltage line controlling n n n Additional informationAdditional n n n The typical design SVC lifetime is to 20 30 years protection may need be to replaced earlier condition on depending examples Project n n
. .
.
. .
. 10kV) and 10kV) . g . . If a transformer . These systems may may These systems . . Six-pulse are SVCs . . . The reactors and capacitors are usually SVCs areSVCs made up 500kV to and 720MVAr; and they have been in operation for many years at higher ratings and voltages than STATCOMs SVCs tendSVCs be to cheaper on a than STATCOMs like-for-like basis, but have a larger footprint impacts and Dependencies normally that harmonics produce TCRs The require fifth and seventh harmonic filters, and third block to transformers winding star-delta and ninth harmonics concern and space there’s where but typical, pulse twelve performance, harmonic about canSVCs be considered A step-up transformer is usually required to couple the the to SVC required bus section fails, the will SVC be out of service until the replaced or repaired is transformer The fast dynamic response of the is SVC provided thyristor by valves that are water indoor for designed and insulated air cooled, use housed outdoors unless there are noise considerations is it HVDC) and generators turbines, wind important ensure to that interaction between the control systems is identified at the design stage and avoided reliabilitySVC is heavily dependent on the LVAC (cooling, auxiliary of availability systems and power supply) and spare parts provision power the for needed are systems Auxiliary building any and cooling converter electronic systems conditioning air availability overall improve help to duplicated be Where dynamic voltage control is being is control voltage dynamic Where deployed in close electrical proximity other to as (such systems control electronic power Electricity Statement Year Ten 2015 the capability handle to the reactive power flow and block triplen harmonics These are specialised transformers with low low with transformers specialised are These secondary (e voltage windings Appendix E (via a step-up transformer) are already in in already are transformer) astep-up (via ±200MVAr of ratings at STATCOMs are increasingly being deployed Capabilities power quality improve to harmonics and flicker control also design and dynamic response means it can reactors and capacitors static network the the voltage waveform needed to compensation (IGCTs) to manufacture thyristor commutated gate (IGBTs) insulated or transistor bipolar gate converters (VSC), typically using insulated source voltage STATCOMs on based are 0 and lag factor 0 between compliance dynamic Operator/Transmission Owner Code (STC) connection interface point to achieve System STATCOMof onshore/offshore the at is dynamic voltage control system (FACTS) providing fast responding A STATCOM transmission AC aflexible is ) ABB of courtesy (image STATCOM 32MVAr E9.1 Figure (SVC).Compensators VAR Static or capacitor reactors banks, reactive powerabsorb AC quickly than more or power device generate which can electronic CompensatorA Static (STATCOM) acting is afast 2015 Ten Year Statement Electricity Static compensator (STATCOM) compensator Static E9 – Appendix Their design can also incorporate incorporate also can design .Their . . 95 power factor lead factor power 95 Applications at 220kV 220kV at .Applications . A application typical The STATCOM .The . 95 power power 95 .
transformer to provide an economical design economical an to provide transformer at transmission with higher voltages need a medium voltages (e at atransformer without grid to the directly connect can STATCOM that voltage devices technology has led to the introduction of high VSC HVDC in developments Recent in performance although there will be a slight compromise solution than a fully rated STATCOM alone, acheaper to provide banks capacitor and reactors fixed with integrated be can ratings source converter generate their own response via the voltage they because systems, level circuit short low or networks weak for STATCOMs suitable are in response to voltage rises or depressions network voltage by controlling the MVAr output voltage by controlling the MVAr output or local can control the MVAr output or local network 2015 January in announced was Kenya in project a±300MVAr and service . . STATCOMs with reduced . g .
33kV) The STATCOM .The . Applications
. . 26 Appendix E 27
. Supplied . . . EWEC 2007 . 19, 1999 CIGRÉ 2008 Session 2008 CIGRÉ . . . . Chondrogiannis et al CIGRÉ WG14 paper B4_305 large of connection AC compliant Grid Statcom, a using farms wind offshore S Static TB144 – Brochure Technical CIGRÉ (STATCOM), compensator Synchronous Guillaume de Préville, Wind farm Wind Préville, de Guillaume integration in large power systems; D-Statcom of Dimensioning parameters code grid meet to type solutions requirements Greater Gabbard Windfarm 50MVAr +/- PLUS withSVC MSC and MSR, supplied by Siemens by installed and supplied +/-200MVAr Electronic Power Rongxin Dong Guang, China 220kV connection, connection, 220kV China Guang, Dong Holly STATCOM comprises a +110/-80MVAr +110/-80MVAr a comprises STATCOM Holly togetherVSC, with capacitor banks and filtersto givetotal a range of 80MVAr capacitive 200MVAr to inductive and installed ABB by . 138kV ±100MVAr Talegat: SDG&E by installed and supplied STATCOM, Electric Mitsubishi n n Additional informationAdditional n Project Examples Project n and keeping replacement parts on site n This can often be increased adding by STATCOM the within modules redundant n n
.
.
. . Usually, Usually, .
. These systems may may These systems . . STATCOMS should be designed be should STATCOMS . However, the equipment needs to be to needs equipment the However,
. . Dependencies and impacts and Dependencies are designedSTATCOMs be to installed in a building or enclosure, not outside not enclosure, or building a Electricity Statement Year Ten 2015 a step-up transformer couples the STATCOM at especially voltage, bus required the to voltages transmission can be combinedSTATCOMs with banks, (MSC) capacitor switched mechanically and (MSR) reactors switched mechanically thyristor switched capacitor (TSC) banks into compliant technically and cost-effective a scheme adequately rated and designed for continuous capacitor bank and reactor switching for the solution meet to and STC Grid Code dynamic harmonic requirements and being is control voltage dynamic Where deployed in close electrical proximity other to wind as (such systems control electronic power turbines, generators and HVDC) it is important ensureto that interaction between the control systems is identified at the design stage and avoided Auxiliary systems are essential for the power building any and cooling converter electronic systems conditioning air reliability overall improve help to duplicated be The typical design lifetime is 30 to 20 years and availability of spare components spare of availability and to haveto an availability rate of above 98% Cooling systems, control and protection may on depending earlier replaced be to need condition system auxiliary the on dependent is Reliability supply) power and LVAC (cooling, Appendix E and mitigated and network complexities must be analysed transmission lines, but before it is installed an alternative to building new or additional Sometimes, series compensation can be Capacitors) Nokian of courtesy (image installation compensation Series Figure E10.1 required. is (POD) damping flow, or power system stability increased oscillation power increased lines where in transmission long world, the systems typically around transmission compensation (SC) inSeries many is widely used 2015 Ten Year Statement Electricity Series compensation E10Appendix – .
installed on insulated platforms above ground an economic solution, the equipment is to provide so lines; transmission existing the with series in voltage, system at operates SC
28 . Appendix E
. 29
. As the valves . . So compensating by the . Since the series capacitor in continuous operation) there is no need no is there operation) continuous in series reactance using a series capacitor, the than shorter electrically be to appears circuit it really is and a higher active power transfer can be achieved output its that means which – self-regulated is the to proportional control) (without directly is line current itself – it will also partly balance the voltage drop caused the by transfer reactance the stability of voltage the Consequently, raised is system transmission The TPSC is similar a FSC in to that it has only a fixed value of capacitance, but using thyristor valves and a damping circuit may allow the capacitors be to returned service to faster than FSCs after fault recovery conditions fault during only operational are (compared thoseto of a TSCS, which are for a fluid cooling system. Capabilities In a transmission system, the maximum active power that can be transferred over a power series the to proportional inversely is line reactance of the line . .
. . It can
In some In . . . . One drawback of the TCSC is that Thyristor controlled series capacitors (TCSC) capacitors series controlled Thyristor Fixed series capacitors (FSC) capacitors series Fixed Figure E10.2 Figure Simplified model of transmission system with series compensation n There are two main types of series compensation: n The TCSC installation is more adaptable A third design developed Siemens by is called (TPSC) capacitors series protected thyristor The FSC isthe simplest and most widely used design as it has a fixed capacitance that is switched in and out using a bypass switch line transmission the through current load The directly “drives” the MVAr output from compensation the makes and capacitor the “self-regulating” vary the percentage of compensation using by a thyristor controlled reactor (TCR) and has the potential manage to or control power system and oscillations power as such conditions (SSR) resonance sub-synchronous Electricity Statement Year Ten 2015 designs, it may also allow the capacitors be to returned service to faster than FSCs after fault recovery they operational, always are valves the because must be continuously cooled a fluid by filled system cooling Appendix E n n n network: the installation of the SC on the GB power with identified been have challenges Several Transmission’s transmission networks in 2015 commissioned on the National Grid and SP been have SC of installations first The Dependencies and impacts months 18-24 and manufacturing lead times of around design with suppliers, of anumber are There required are testing and modelling significant means operation their of SVCs and capacitors The technology is comparable to shunt Availability n n n n ofcapability compensation series including: Thyristor control further enhances the n n n n provide: help can Installing the series capacitors on the network 2015 Ten Year Statement Electricity Interaction with other control systems Transient recovery voltage study voltage recovery Transient Impact on existing protection and control and protection existing on Impact damping Electromechanical power oscillation Mitigation of SSR Improved capacitor bank protection bank capacitor Improved Smooth control of power flow power of control Smooth Improved load sharing between parallel lines power balance reactive and regulation voltage Improved transmission systems of stability Increased dynamic power Increased transmission capacity Series compensation E10Appendix – . . However, the complexity complexity .However, the .
.
.
. n n Project examples SC the to accommodate changed and reviewed be circuits under fault conditions so settings must adjacent of equipment protection affect can SC to generators hazards potential to avoid and introducing series capacitors into the network of effects the to understand required is analysis maintained are SC of advantages the that to ensure considered aboutConcerns SSR should be carefully n Additional information n – Finland (TCSC) transmission capacity between Sweden and increased SC: power 400kV Isovaara The – (FSC) BRAZIL South Interconnection III, North 2008 Compensation, WG 14 Compensation, Series Controlled TB123CIGRÉ –Thyristor Networks, WG B510, 2010Networks, Apr Monitoring of Series Compensated and TB411 Control CIGRÉ –Protection, with possible system faults power transmission stability in conjunction to its thermal limit without jeopardizing its existing power corridor to operate closer conditions grid transient as well as state steady at and Finland by increasing voltage stability existing power corridor between Sweden the power transmission capacity of an installation was designed to increase Grid National Swedish 400kV the in installed was A 515MVAr capacitor series 51–70% between of compensation across the circuits ranged 14 months within substations five at installed were 130–343MVAr (FSCs) capacitors series fixed five problems, stability voltage and To losses avoid . . Series compensation allows the Complex network network .Complex . 18, 1997 Dec . The degree degree .The . . This .This . 30 Appendix E 31
. The principle is allow to The technology is relatively relatively is technology The . . These devices are employed . in the circuit the in simple using a series winding to provide provide to series winding a using simple impedance additional hence and inductance a system fault manageto the current safe to levels for switchgear operate to two sections of the network be to connected having reliability without improving together, increaseto the overall short circuit level and switchgear replace . QBs Appendix E11 – Quadrature E11 Appendix boosters and series reactors . Series reactors are employed limit to the short circuit current which can flow following Quadrature boosters which are a particular a are which boosters Quadrature type of phase-shifting transformer (PST) are used increase to or decrease the power flow in a particular circuit within a network improve the load current sharing between failure, circuit a particular in following circuits, thereby increasing overall system load flow capability Figure E11.1 Quadrature boosters (QBs) and seriesQuadrature boosters reactors (QBs) are networks. loaded used congested and in heavily Electricity Statement Year Ten 2015 Appendix E around 24 months of times lead manufacturing and design with challenges transport and testing significant representing system) the on equipment of items heaviest (the devices large very are these requirements transformers power The technology is comparable to normal Availability phase components to facilitate transport single three into split are units rated higher 3000MVA exceed can and circuit to the worldwide use in largest the amongst are and circuit the 2750MVA of to match rating athroughput have 400kV at system transmission the on employed in operate they networks the for designed specifically are reactors series and QBs transformers, Like Capabilities and asset management require the essentially same maintenance technology to power transformers and Both utilise equipment similar types the real power transmitted and flow current the reduce or increase injected voltage, which is used to either controls the direction and magnitude of changing the load current thereby phase, third the into avoltage inject phases two that such configured transformer aseries and (exciter) ashunt of consists A QB 2015 Ten Year Statement Electricity . There are a number of suppliers, suppliers, of anumber are .There boosters and series reactors series and boosters Appendix E11 –Quadrature Series reactor Series ratings are matched The highest capability QBs QBs capability highest .The . However, to meet system system .However, to meet . . . A tap changer
The .The
.
to be fully analysed at the design stage design the at analysed fully to be transmission system have failed the of parts other when intended as used being are they when flows power reactive significant cause can reactors series and QBs fault conditions high loads are only experienced under system consume load electricity when carrying and only they because efficient particularly are reactors Series high. very still is efficiency site, to units the to transport requirement by the limited is size although and QBs; of loss load available technology is used to reduce the no- formula cost life awhole using minimum economic to an kept are reactors series and by QBs caused losses electrical The reactors series to switch tested and rated associated circuit breakers to need be suitably the and arresters; surge with controlled be transients during switching, which need to voltage high cause can reactors series and duty busbar or circuit the for rated be loads high at cooling forced for power site for arequirement and transients, to voltage sensitivity including issues, same the to susceptible are and technology, transformer Both applications are fundamentally based on Dependencies and impacts n n Additional information Shifting TransformersShifting Phase- of and Testing Specification Application, the for Guide 62032 IEC 6: Reactors Part – transformers Power 60076-6 IEC .
The best best .The Both need to to need .Both . These need These need QBs .QBs
. .
32 Appendix E 33
. (Rev 5 Accessed 9 September 2015) Figure E12.1 (image courtesy of Prysmian)
.
.
. com/public/ab02245fb5b5ec41c12575c4004a76d0/XLPE%20Land%20Cable%20Systems%20 . pdf . abb . e . The table below shows shows below table The . It also helps cancel magnetic magnetic cancel helps also It Each cable has its its has cable Each . 1 . Aluminium is used mainly used is Aluminium . . Appendix E12 – Appendix E12 threeSubmarine corecables . There is also the option . 2GM5007GB%20rev%205 ABB, XLPE Land Cable Systems User Guide (Rev (Online 1) – Now at Rev 5) Available: https://library Available: cable systems for the stated power transfers and are for indicative purposes only; actual cable system designs will vary from project to project 1 (usually with XLPE insulation) in a single and over-sheath common with cable armouring of incorporating fibre optic cables for communications own lead sheath stop to water getting in conductor the as used generally is Copper for subsea cables as it has a lower resistance aluminium than Three core cables AC comprise three cables core single individually insulated Three core HVAC cables (hereafter HV submarineThree core HVAC connect offshorecables) farms wind are that close transfer power low relatively shore and have to requirements. fields, which cuts losses in the steel wire circulating induced the reduces and armour currents that de-rate the cable system for land cables reduce to the cost and weight of the cable, at the price of a reduction in rating approximately (of for 20% a given section) cross but laying x 1c) (3 a complete circuit in one cheaper is trench Three core HV submarine cables are not where applications, onshore for used generally their size and weight makes them impractical due the to number of joints required and difficulties in transport. Three single core cablesAC are usually used instead A three core cable x 3c) is larger (1 and heavier than the equivalent three single core cables Electricity Statement Year Ten 2015 Capabilities Three core HV submarine cables are available in voltages up 420kV to (400kV nominal)and transfers550MW Appendix E 2 burial 1 15˚C, temperature soil sea table: above the The following assumptions were made for E12.1 Table 2015 Ten Year Statement Electricity Prysmian, Nexans and NKT and Nexans Prysmian, years to two one of Supply and installation times are in the region Availability increased capacities on the same cables and 245kV respectively, allowing slightly ratings 2 1and references from taken been has data armour wire steel conductor, (Rev 5 Accessed 9 September 2015) 9September Guide 5Accessed User (Rev Systems Cable toXLPE Attachment Systems, Cable Submarine XLPE ABB, Available: http://new 132kV and 220kV are the nominal voltage voltage nominal the are .132kV 220kV and Capacity (MW) 1000 100 150 200 300 400 500 600 800 These cables can operate up to 145kV up operate can cables .These . 0m, thermal resistivity 1kW/m, copper Submarine three core cables core Submarine three E12Appendix – . abb Suppliers include ABB, ABB, include .Suppliers . Voltage com/docs/default-source/ewea-doc/xlpe-submarine-cable-systems-2gm5007 (kV) 132 132 132 220 132 220 132 220 132 220 132 220 132 220 132 220 . The capacities capacities .The
of cables required Number 1 1 1 1 2 1 2 2 3 2 3 2 4 3 5 3 .
longer cable lengths power transferred reduces dramatically for real maximum the transmission AC cable for considered threshold distance, HVDC links should be transmitted decreases be can that power active of amount the and of capacitive charging current increases amount the so increases, length cable the As cable the of ends both or one at reactors, shunt of form the in equipment, compensation reactive need and use AC system for intended are cables submarine HV core Three Dependencies and impacts Cross (mm²) 1000 1000 1000 1000 1000 1000 300 500 300 500 800 300 630 500 800 630 . The following graph shows how (Rev 1) (Online – Now at Rev 5) Rev at –Now 1) (Online .(Rev Weight (kg/m) . 3x104 2x58 2x85 2x67 3x65 2x81 3x85 2x95 4x85 3x87 5x85 48 58 85 67 95 . Beyond a certain . pdf?sfvrsn=2 Diameter 2x176 2x206 2x204 3x185 2x219 3x206 2x234 4x206 3x224 5x206 3x241 (mm) 167 176 206 204 234 . .
34
Appendix E 200 35
.
.
. Beyond this, 150
132kV 50/50 220kV 50/50 100 multiple cables will have be to considered Close bundling of the three phases in three core cables removes this an to extent for current as however currents; cable smaller effect becomes de-rating the increases significant. A cross sectional1,000mm² area of largest the to corresponds probably (copper) practically permissible current rating for this type of cable that would be capable of 400MW transfers per cable at 245kV This should be weighed up against the cost for a HVDC system or single core cables AC km . 220kV 70/30 132kV 70/30
50 . . For land
220kV 100/0 132kV 100/0 0 0
50
300 250 200 150 100 400 350 MW The circulating currents generated in the on limitation another are sheath metal three core cable AC capacities cable routes, this is largely mitigated by bonding sheath special of application the arrangements, but it is impossible apply to these submarine to cable systems The 100/0 scenario is the cheapest but also the the also but cheapest the is scenario 100/0 The compensation reactive the all as effective; least on requirements weight the onshore, placed is substantially reduced are platform offshore the Figure E12.2 Maximum real power transfer and in 132kV 220kV cables with 100/0, 50/50 and 70/30reactive compensation split between onshore and offshore. (1000mm² copper cross section) Electricity Statement Year Ten 2015 Appendix E 5 4 3 n n Project examples – Commissioned 2015 Ten Year Statement Electricity 6 belt%20brochure%202GM8001-gb%20korr3 Available: http://www05.abb.com/global/scot/scot245.nsf/veritydisplay/689213765eef0d49c1257c0e00243c4f/$file/Little%20 2015) 9September (Accessed: ABB, World’s most powerful three-core submarine cable: Little Belt Visual Enhancement Scheme, Denmark (online) (online) Offshore and On- for Solutions Transmission Energy Intelligent NKT, Prysmian, Linking People, Places, Projects and Passion – a Journey through Prysmian Group (online) (online) project farm wind offshore Array London the for contract cable power Euro million 100 wind Nexans Nexans, Available: http://www.nexans.com/Corporate/2009/Nexans%20London%20Array_%20GB.pdf 2015) 9September (Accessed: Available: http://www.nktcables.com/~/media/Files/NktCables/download%20files/com/Offshore_Flyer.pdf (800mm² CU). (800mm² by Prysmian supplied cables AC submarine (2012): Greater Gabbard offshore wind farm length). main CU 47-48km 630mm² and end 3km each at CU (800mm² Nexans by supplied cables AC submarine x 3-core (2012): farm London Array Phase-1 wind offshore 504MW, 132kV, 3-core 3x160km Submarine three core cables core Submarine three E12Appendix – 630MW, 150kV (max 170kV), 4 150kV (max 630MW, 4 . .
. pdf 3
n n . by ABB 3-core AC submarine supplied cables 2x7 420kV), 1100MW, (max 400kV BeltLittle in project (2013): Denmark . diameter) 270mm AI, (1600mm² by NKT supplied cable submarine a24 245kV), (max 220kV windAnholt (2013): farm offshore (Accessed: 9 September 2015) 9September .(Accessed: 6 5 . . 5km 3-core AC AC 3-core 5km .
. 400MW, 400MW, . . 5km 5km
36 Appendix E 37 .
. For submarine For . 500kV, however, is . 500kV, however,
. (Accessed: 9 September ) 2015 Figure E13.1 (image courtesy of ABB) transfers of less than 300MW, three core AC core single over considered be cables should a non-standard voltage level on the electricity the on level voltage non-standard a transmission system in GB; 400/275kV cables are commonly used onshore and the use of a standard system voltage would remove the transformers onshore for need Capabilities Single core, XLPE insulated cables are available up 500kV to voltage levels . Comellini, Challenges of the Second Submarine
. .
2 . Stenseth, R
. ; however there there however ; 1 . Mansouri, K . . Lead is favoured . . Denche, F . They have mainly used . . Land cable sheaths are usually Appendix E13 – Appendix E13 core cables single Submarine . Granandino, J . Prieto, G Available: http://www.jicable.org/TOUT_JICABLE_FIRST_PAGE/2007/2007-A9-1_page1.pdf Available: R Interconnection Between Spain And Morocco, Presented at Jicable 2007 (online) Aspects, Environmental Repair, Installation, Design, Cables: Power Submarine Worzyk, Thomas Published 2009 ISBN 978-3-642-01270-9 is no technical reason why they should not be used on longer routes with the correct levels of reactive compensation metallic the bond effectively to inability The currents circulating reduce to sheaths to source heat additional an adds (which the cable) would mean significantly reduced ratings relative their to land equivalent cables and high magnetic losses in steel armour Alternative designs of armouring have been have armouring of designs Alternative less (or copper non-magnetic as such used, provides which alloy), aluminium usually, a low resistance return path as well as armour the in losses magnetic removing 1 2 For larger area conductors, above 1000 mm² or segmental a so, strandedconductor is used reduceto the skin effect resulting from higher currentsAC impact the mitigate to cross-bonded currents circulating of rarely cables have submarine HV core Single been used for submarine applications and have so far been used only for very short distances, up around to 50km low pressure oil filledtechnology, such as the interconnection Spain-Morocco Single core HVAC submarine cables (hereafter coreSingle HVAC areHV submarine used widely onshore cables) in (usually a conductor consist of They networks. and mainly lead XLPE) a (now insulation copper); or aluminium sheath to stop moisture getting stop sheathor aluminium to – in cable other all designs. similar to Electricity Statement Year Ten 2015 This has a significant cost implication in cable copper much as twice as manufacture is used per unit length over aluminium as a sheath material for cablessubmarine Appendix E armour wire copper using 10m apart least at laid are cables Submarine formation. aflat in apart cables) (three AC circuit asingle upon based are Transfers thermal resistivity 1kW/m, copper conductor 1.0m, 15˚C, burial temperature Soil/seabed table above: The following assumptions were made for the E13.1 Table 2015 Ten Year Statement Electricity 5 4 3 characteristics are derived from unavailability single cablefails, all but eliminating circuit a if used be can that cable redundant one with installed often are cables core single (see ‘Land installation’ appendix) understood well are rates failure cable Land comparable cross section a of cables core three than rating thermal ahigher have AC cables core single laying, Because of their construction and spaced Capacity Available: http://new 2015) 9September 5Accessed (Rev ABB, XLPE Submarine Cable Systems, Attachment to XLPE Cable Systems User Guide User Systems Cable toXLPE Attachment Systems, Cable Submarine XLPE ABB, Available: https://library (Rev guide User’s Systems Cable Land XLPE ABB, International Electrotechnical Committee, IEC 60287: Electric Cables – Calculation of the Current Rating 2GM5007GB%20rev%205 (MW) 1000 500 400 300 200 100 . Ratings calculated from Submarine single cables core E13Appendix – . On land cables are laid 200mm 200mm laid are cables land .On Voltage 400 400 275 220 (kV) 275 220 275 220 132 220 132 132 . abb . e . . com/docs/default-source/ewea-doc/xlpe-submarine-cable-systems-2gm5007 abb . pdf . com/public/ab02245fb5b5ec41c12575c4004a76d0/XLPE%20Land%20Cable%20Systems%20 . section Cross (mm²) 1400 1000 1000 300 630 400 630 240 400 N/A N/A N/A
4 . 3 and and Submarine . Physical Submarine 5 . Weight (kg/m) 1) (Online – Now at Rev 5) Rev at –Now .1) (Online N/A N/A N/A 47 33 32 38 30 31 26 27 36 .
Diameter increased increases as the cable operating voltage is length increases transferred reduces dramatically as cable cable transmission the real maximum power AC for how shows graph following The be considered threshold distance,certain HVDC links should route length and operating voltage compensation required depends on the cable effects capacitive mitigate compensation equipment to be installed to reactive require also may cables submarine HV core single cables, core three Like Dependencies and impacts and Sudkable NKT Suppliers include ABB, Prysmian, Nexans, Availability at higher voltages than three core cables core three than voltages higher at operate generally they as cables core single for (mm) 138 131 115 122 112 113 106 109 120 N/A N/A N/A (Rev 5 Accessed 9 September 2015) 9September 5Accessed .(Rev . This is effect more pronounced section Cross (mm²) . 1400 1200 1200 400 800 500 800 300 500 240 630 185 . The charging current also (Rev 1) (Online – Now at Rev 5) Rev at –Now 1) (Online .(Rev . The amount of of amount .The Weight (kg/m) Land 24 14 15 19 12 15 10 11 16 10 . 8 5 . pdf?sfvrsn=2 . Beyond a Diameter
(mm) 123 109 109 . 99 91 97 90 80 89 88 74 64 .
38
Appendix E 200 39
. 150 275kV 50/50 400kV 50/50
. 100 possible to install compensation mid-route mid-route compensation install to possible necessaryif It is more economical use to three core cabling connections submarine rated lower for km
400kV 70/30 275kV 70/30 50 400kV 100/0 275kV 100/0
. For land cables it is 0 0
600 500 400 300 200 100 900 800 700
1000 MW The 100/0 scenario is the cheapest but but cheapest the is scenario 100/0 The also the least effective – as all the reactive weight the onshore, placed is compensation requirements on the offshore platform are reduced substantially Figure E13.2 Maximum real power transfer and 400kV in 275kV cables with 100/0, 50/50 and 70/30reactive compensation split between onshore and offshore (1000mm² copper cross section) Electricity Statement Year Ten 2015 Appendix E 8 7 6 n n n Project examples – Commissioned 2015 Ten Year Statement Electricity 10 10 9 belt%20brochure%202GM8001-gb%20korr3 Available: http://www05.abb.com/global/scot/scot245.nsf/veritydisplay/689213765eef0d49c1257c0e00243c4f/$file/Little%20(9 September 2015) NKT, Intelligent Energy Transmission Solutions for On- and Offshore (online) Offshore and On- for Solutions Transmission Energy Intelligent NKT, ABB, World’s most powerful three-core submarine cable: Little Belt Visual Enhancement Scheme, Denmark (online) (online) USA York Harbor, New project, Centre Energy Bayonne system: cable XLPE AC submarine 345kV longest World’s ABB, Available: http://www (online) Angoulevant 2010, Olivier September 15th March 2015) 2010 Bergen, China Wind Offshore Angoulevant, Olivier Nexans, 2b7372bc835e78e6c125798800454000/$FILE/Project+Bayonne+US+345+kV+XLPE+subm Available: http://www04 2015) 9 September (Accessed: Available: http://www.nktcables.com/~/media/Files/NktCables/download%20files/com/Offshore_Flyer.pdf Prysmian, Prysmian: Euro 300 Million Contract Awarded By Terna for the Development of a New Submarine Power Link between between Link Power Submarine aNew of Development Sicily and the Italian for Mainland (online) Terna By Awarded Contract Million 300 Euro Prysmian: Prysmian, Available: http://investoren . by ABB supplied submarine and underground are cables single-core underground cables 3x1 cables, submarine core . by ABB supplied submarine and underground are cables 1100MW, 400kV (max 420kV), 6x5 420kV), 1100MW, (max 400kV BeltLittle in project (2013): Denmark 345kV, 3x10602MVA, Bayonne Centre (2011): project Energy by Nexans supplied CU) (3 x1200 mm² cable submarine core single 3x2 420kV), (max 1000MW, 400kV grid connection (2008): Lange Orman AC single core underground cables Submarine single cables core E13Appendix – .
.
. norway . abb 7 . prysmian . . cn/PageFiles/391359/Nexans%20-%20Olivier%20Angoulevant com/global/seitp/seitp202 .
. . (Accessed: 9 September 2015) 4km AC single- 4km . 6 . com/phoenix . 066km AC AC 066km . . The AC pdf . . 8 . . 5km 5km zhtml?c=211070&p=irol-newsCorporateArticle&ID=1366416&highlight= 4km AC AC 4km The The
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. n construction –Under examples Project n
supplied by NKT supplied CU) mm² (3 x800 cables submarine core UK: in farm wind offshore yMôr Gwynt supplied by Prysmian submarine and underground are cables 6x5 and cables submarine core AC single 6 x38km Sicily – Italy mainland: be commissioned in 2014 576MW, 132kV, AC single 3x85km (Accessed: 9 September 2015) 9September .(Accessed: . 4km underground cables underground 4km . 9 . pdf This project is expected to to expected is project This . pdf . 10
2000MW, 380kV, .
.
(Accessed: 9 9 .(Accessed: .
The .The . 40
Appendix E 41
. . Figure E14.1 Cable carousel on Nexans Skagerrak (image courtesy of Nexans)
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.
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. Accessed 9 September 2015
2 . In shallower waters, waters, shallower In 1 . uk/cawp/ . . Where burial is too 21, Technical Brochure TB 398, 398, TB Brochure Technical 21, co . . CIGRÉ propose a method method a propose CIGRÉ . abb . . A separate vessel could be .
Appendix E14 – Appendix E14 & DC AC installation cable Subsea . The depth and burial method chosen method burial and depth The . Available: http://www Available: World’s largest cable-laying vessel joins ABB (online) B1 Group Working CIGRE 2009 December Cables, Submarine and Underground to Damage Third-Party installation is usually from modified barges with capacities turntable reduced considerably length of cable that can be installed in a single of dimensions and mass the on depends pass the cable and the capacity of the laying vessel To protect themTo from fishing gear or anchor strikes, cables are usually buried at a metre or more beneath theseabed using jetting that fluidises the soil, or a cable plough or rock ripping Where vessel capacity is insufficientto lay in a single pass, offshore cable jointing will be necessary potentially and complex are operations Joining minimised be should time-consuming and where possible used allow to restocking offshore, so the laying vessel would not have return to to port to restock challenging – for instance, if the seabed is solid rock – cable can be protected rock by mattressing concrete or placement/dumping The appropriate burial depth is determined by anchors, dragging as such considering risks disturbance from fishing activities and seabed mobilitysediment for submarine power cables depends on seabed conditions such as soft as such conditions seabed on depends sand and clay or chalk for determining acceptable protection levels 1 2 Deep water submarine cables are installed from from installed are cables submarine water Deep turntable with vessels cable-laying dedicated capacities of up 9000T to Installing submarineInstalling cables a very is challenging operation be carefully and considered should before starting project. any A detailed survey and selecting an appropriate are route particularly important. Electricity Statement Year Ten 2015 Appendix E timetables and costs project impact positively may which vessel, laying main to the vessel aseparate on also possible to jointing perform operations operations jointing offshore of number the to way reduce acost-effective be may necessary, separate burial in multiple passes challenging more made is a fault is there if cable the of recovery subsequent required at sea, although the installation and is vessel laying acable time the reduces it as preferred be may cables, core single than rather HVAC cables, core three or links, HVDC of case the in cables bipole bundled of use The cable installation costs calculating when consider to factors significant are winter) the in time the of 40% (around demobilisation costs and poor sea conditions cable jointing operations, mobilisation and rock ripping, ploughing) (jetting, used technologies burial the influence factor, but changing seabed structure can asignificant not is depth Water suitable. are conditions sea if aweek days day, seven a hours four twenty operate can Vessels it is buried until cable unprotected the guard can vessels 3 sea at time less for required is vessel laying expensive large, the as economical more to be prove can approach (this installation in stage alater at vessel by the main installation vessel or by a smaller seabeds all for suitable be not may but operation afaster generally simultaneously and burying laying when average is 200m/hr but possible are to 500m/hr up of rates laying Cable Capabilities 2015 Ten Year Statement Electricity 5 4 Prysmian CIGRE Working Group B1 642-01270-9 Thomas Worzyk, Submarine Power Cables: Design, Installation, Repair, Environmental Aspects, Published 2009 ISBN 978-3- Available: http://prysmiangroup.com/en/business_markets/markets/hv-and-submarine/about_us/cableship-giulio-verne/ 2009 April Systems, Cable . Cableship Giulio Verne (online) . . . Subsea cable installation AC & DC E14Appendix – 3 3 ) If this approach is taken, taken, is approach this .If . 10, Technical Brochure TB 379: Update of of Experience HV Service Underground and Submarine . . Cables may be buried buried be may .Cables
. Downtime during . Ploughing is . If jointing is is jointing .If (Accessed: 9 September 2015) It is is .It
(image courtesy IHC Engineering Business) Engineering IHC courtesy (image plough cable 4power Stallion Sea E14.2 Figure months two of to repair Typical failure rates for subsea cables are 0 are cables subsea for rates failure Typical best solution the to identify order in study engineering own its requires therefore and unique to be tends project cable HVAC or submarine HVDC Each cross section for necessary bundled cables conductor in increase the given cable the of installation costs against increases in the cost most economic laying arrangement, weighing the establish to analysis cost-benefit detailed appendices these in to stated 25% up that over rating increase can heating effects to mutual due system cable the of rating overall the reduce also can cables Bundling to 40 years to 40 30 of lifetime expected an have systems cable considerably with local conditions failures per 100km per year per 100km per failures .
. 3 .
. Laying the separately cables Each project needs a a needs project .Each 5 but this could vary vary could this but 4 , with a mean time time amean , with . Submarine . 1 1 . 42 Appendix E 43 ), Protectorsheel), ® Mattressing is Mattressing . All of them have . Companies providing providing Companies . . . It is harder manufacture to Companies providing diving providing Companies .
. . Tubular products are widely used in Manufacturers of mattresses/blankets include mattresses/blankets of Manufacturers and Pipeshield Flexiform), (Submat SLP (MassivMesh) FoundOcean readily available in stock or can be made to order in a relatively short timescale subject to demand oil and industry telecommunications global the including manufacturers with sectors gas and Offshore (Uraduct Trelleborg vessels and services and Marine, vessels Briggs include MarineTrico and TS Marine crossings pipeline of experience considerable in the oil and gas sectors services include Hughes, REDS, Red7Marine Red7Marine services REDS, Hughes, include and such ROVs as Subsea Vision, Osiris, Fugro both of combination a or from MSD Services and Uraprotect from Dongwon En-Tec larger diameter sections for use with undersea cabling HVAC
.
. 5 cit) . . (Accessed: 9 September 2015) The majority of majority of The . . Giulio Verne e . respectively 6 . Nexans, Skagerrak cable-laying vessel (online) Available: http://www.nexans.com/eservice/Corporate-en/navigate_224932/Skagerrak_cable_laying_vessel.html Available: and Skagerrakand 6 Figure E14.3 Rock Placement (image courtesy of Tideway) Availability Subocean Group, Global Marine Systems Limited and Visser & Smit Marine Contracting have been the main installers of subsea cables on UK offshore wind farms date to Manufacturers Prysmian and Nexans also also Nexans and Prysmian Manufacturers own and operate vessels i Electricity Statement Year Ten 2015 current cable laying vessels have a carousel a have vessels laying cable current capacity from up 4,000 to 1,000 tons but those owned the by cable manufacturers have a carousel capacity tons (op up 7,000 to Other companies with experience in telecoms telecoms in experience with companies Other cables and oil and gas who are now involved in offshore wind include Marine, CTC L D Travocean, Tideway and 5 Oceans Services and new ships are finding their way into the industry Appendix E identify where liability lies if there are problems to difficult be may it as installation, and supply cable separate for used are parties separate recommended hence cables, may introduce a heat source that could could that source aheat introduce may cables, power particularly assets, subsea other that products or rock dumping protective tubular mattresses, concrete of use necessary, it can be accomplished through the pipelines or cables other as such obstacles subsea crossing the to avoid Wherever possible, routes should be chosen heating solar to minimise aplatform of side north the on these to sit best be may it and connecting the to cables offshore platforms Jtubes the in occur may system cable entire Thermal bottlenecks that effectively de-rate the forces dynamic the for account fully not may testing swells in motion vessel of impact on cable weight, depth of installation and the wheel laying the over (SWP) pressure wall side and tension cable cables to the damage of arisk always is there and large, are The forces involved in offshore cable installation commitments of apipeline requires vessels new in investment offshore wind projects going ahead of certainty by the dictated be degree to some will vessels such in investment the and limited e offshore, runs cable long waters lay cables short near shore and in shallower can that companies of anumber are There Dependencies and impacts 2015 Ten Year Statement Electricity 7 J . E Skog, NorNed-Innovative Use of ProvenTechnology, Paper 302, CIGRE SC B4 2009Bergen Colloqium 2009Bergen B4 SC CIGRE 302, Paper ProvenTechnology, of Use NorNed-Innovative .Skog, 1 Larger vessels with the capability of of capability the with vessels .Larger and detailed computer modelling is Subsea cable installation AC & DC E14Appendix – Factors to consider included included to consider .Factors . Both of these depend depend these of .Both Care must be taken if if taken be must .Care . . It should be noted g Where it is is it .Where .70-100km, are CIGRÉ type type .CIGRÉ . Justifying Justifying . . 7
n n Project examples areas. fishing and dumps, munitions etc resistivity thermal makeup, temperature, laying such as subsea conditions (seabed cable on impact that restrictions other as well as crossing obstacle consider course of will and essential are surveys route cable Detailed by barge to site supplied mattresses with effective, cost more be would crossings together in an installation programme vessel laying cable the on time down minimising advance, in done be typically but obstacle crossing using mattresses would operations laying cable subsea during fitted situ in encountered may be disused pipes/cables left owner obstacle the with negotiated to be need so, may to do used method the and obstacle, an to cross rights are more telecommunications cables there Channel English the towards but Sea, North the in predominant are pipelines gas and area sea particular the as well as point, routes, landfall and desired onshore connection location of the offshore substation, cable the on depend will obstacles of number The is appropriately designed cause a thermal bottleneck unless the crossing NorNed HVDC cable yMôr Gwynt Anholt, Shoal,Sheringham Walney 2 and Ormonde, Rev2, Horns Beatrice, Rough, Westermost Nysted, Thanet, Greater Gabbard, Tubular products are designed to be to be designed are products .Tubular Up to half of obstacles obstacles of to half .Up . . . Putting several several .Putting . . The The Oil .Oil . ), 44 Appendix E 45
Figure E15.1 under construction substation Thanet (image courtesy SLP Engineering)
.
. .
. All types . . Multiple platforms platforms Multiple . . Offshore substation platforms Appendix E15 – Appendix E15 . HVDC platform topside weights are This type of platform’s main function is to provide reactive compensation as cables AC distance transmission economical their reach AC collection platforms collection are generallyAC collect used to there up stepped is generation.wind The voltage difficultto predict as they depend on factors and limitation designs, topside as such type substructures for transmission to shore via AC or DC technology. or DC technology. transmission shorefor AC via to As more gained is experience from AC using explored be may platforms, techniques other offshore transmission using optimise by to AC compensation platforms. that issues vibration mechanical the But come with a lighter platform would have be to traditional more and cheaper before overcome used be could technology AC electrical the Offshore house platforms and collection generation for equipment shore to transmission may be required depending on the project’s capacity and how the platform will be used A separate platform is needed where offshore transmission is via HVDC of platform need cooling radiators, pumps, protection, switchgear, transformers, fans, control and some need living quarters Offshore platforms need extra equipment life- accommodation, emergency including maintenance, for cranes equipment, saving winch hoist to the subsea cables, backup diesel generator, fuel, helipad and the J-tube supports that house the subsea cables as they rise from the seabed the to platform topside, terminated are they where typically platform the on equipment HVDC weighs from 2,000 tonnes over to 5,000 tonnes Electricity Statement Year Ten 2015 Appendix E conditions and platform weight number of legs needed depends on seabed seabed the into piled legs to eight four from range –can ‘jacket’ as –known method them between in bracings tubular with piles or legs four of consists platform HVDC substructureThe supporting for lower rated 2015 Ten Year Statement Electricity platforms, are being introduced alternative designs, such as self-installing increases, platforms larger for need the As wind farm onshore, then transported to the offshore site/ out fitted fully and constructed are platforms All height wave on depending level, sea above metres 40 25 to generally are platforms and deep metres to 50 30 about usually are waters Sea North in commissioning for successful design, construction and overcome to be need that challenges and Each platform has types its own risks design types most than higher are benefits the but method, extra material needed makes it an expensive onto the seabed using ballast materials sunk then and location to out floated are that (GBS) structure based gravity to use is option Another bed. sea the to foundation the roots firmly that installation the during bucket the of cavity the from soil and Using suction buckets involves pumping water more than cheaply pile driving operations sea installedbed in and soil differing conditions, be can they that is platforms self-installing suction bucket technologies associated with barge the off topside the lift then bed sea to the descend legs jack-up hydraulic barge; on a out floated is platform . . These are semi-submersible platforms are These platforms semi-submersible . . Offshore substation platforms substation Offshore E15Appendix – This creates a pressure difference difference a pressure creates This . . An advantage of the the of advantage .An . . Jackets used A self-installing The .The This .This . The The .
North Sea North German the in platforms HVDC of majority the on Yards worked have Nordic where Germany Wolff facilities in Ireland Northern such as Harland & potential and Fife) and Tyneside Lowestoft, in yards (fabrication McNulty and Heerema SLP, from are capabilities UK main The also be extensions to the fabrication facilities development design for and studies feasibility out to carry needed is time extra as years seven about take would above or 1,800MW rating of platform a while years, five about is 1,500MW 1,000MW- between of platform HVDC an for and DC platforms AC both for schedule the impact equipment equipment primary the on depend platforms offshore Construction timescales for AC and HVDC Availability ratings power substation different Table E15 space) more require balanced monopole (a bipolar system would the assumption that the HVDC scheme is a on based usually are sizes platform HVDC . used) is equipment AIS (where platforms DC than populated densely and compact more are they so equipment GIS to use tend AC platforms possible where seas shallow in located are farms wind most hence platform; the of design the in keyfactor another is water the of depth The reinforcement is required additional steel support work and jacket topside, the on space of meter square or tonne equipment it houses the on depends platform the of size The Capabilities There is great amount of experience in in experience of amount great is .There . . 1 gives platform dimensions for for dimensions platform 1 gives . Delivery delays of the primary primary the of delays .Delivery For larger platforms, there could could there platforms, larger .For . The installation timescale . .
For every additional . . . 46 Appendix E . 47
1,800 2,100 3,200 12,000 18,000
Including plant Total weight (tonnes) Total . . W H L Size (m) 74, 64, 38 35, 21, 35 20, 18, 25 31, 18, 39 62, 44, 36 Figure E15.2 DolWin Beta HVDC topsides and jacket (image courtesy of ABB) This supports the message from the industry, that two or three platforms ofa similar design of would be1GW more efficient generation with parallel in built be could they if points dropping or landing as used Platforms must adhere Civil to Aviation Authority (CAA) of level the on impact may which regulations, procedures safety and equipment emergency required An asset life of over 30 50 years to would significantly increase the capital and weight, increased to due cost operational operation/ and specifications anti-corrosion regimes maintenance . Due . . 40+ 40+ 20–40 30–40 30–40 . Due the to Water depth (m) depth Water Electrical equipment equipment Electrical . A combination of installation installation of combination A . As fabrication facilities are . . For platforms lighter than 5,000
And of course installation needs installation course of And . . . The maximum lift capacity for . The largest fabrication yard has a Platform facility 300MW AC 500MW AC 800MW DC 1,000MW DC Accommodation limited, the offshore wind industry has to to industry has wind offshore the limited, compete with the oil and gas sector needs be to provided the by major equipment manufacturers limiting other the are dimensions platform The factor dimension which x 72m, of 340m x 67m supports the claims that a single 2GW+ platform can be constructed must design converter a width, on limitations fit within this constraint. The fabricator would need be to suitably compensated for a single capability foreseeable up taking platform large on their yards the largest vessels had been tonnes, 14,000 but this now been increased with the arrival named (previously Spirit Pioneering the of Pieter Schelte) with a topside lift capacity of 48,000 tonnes and a jacket lift capacity of 25,000 tonnes Dependencies and impacts and Dependencies Platform delivery lead times and capacity and capability yard fabrication on depend and availability as such restrictions, vessel lift capability tonnes, there are more available vessels these industries, other from competition to vessels may have be to booked up two to advance in years vesselscan be used, but differing crane lengths adding by installation offshore complicate can further delays conditions sea and weather favourable serviced previously the have that Suppliers oil and gas sector can construct and install jackets and topsides Table E15.1 dimensions Platform Electricity Statement Year Ten 2015 Appendix E n n n n n n Project examples 2015 Ten Year Statement Electricity n n Additional information n n n n n 924MW 100 x74 GBS 20,000t, x83m, platform: HVDC Beta DolWin 800MW, 62 x 42 x 36m, 15,000t, jacket x42 62 x36m, 800MW, platform: HVDC Alpha DolWin 690MW, 98 x42 12,000t, x28m, 98 self-install 690MW, HelWin Beta HVDC platform: 315MW, 30 Sheringham Shoal: 500MW, 39 x31 39 x18m,500MW, 2,100t, jacket ACGreater Gabbard collector: 300MW, 30 x18 30 300MW, x16m, 1,460t jacket ACThanet platform collector: CIGRÉ Paris Session B3-201, 2008 August Session Paris CIGRÉ J (online) Farms Wind for Substations DNV-OS-J201, Offshore Heerema Zwijndrecht (online) Zwijndrecht Heerema Available: http://hfg Available: http://hfg 17 2014) June (Accessed: (online), Zwijndrecht Heerema Available: http://www Available: http://www Allseas, Pioneering Spirit (online) Financial times (online) article Available: http://www.nordicyards.com/nordicyards.html#_facilities Available: Allseas%20single-lift%20vessel http://www Nordic Yards (online) Nordic Finn, M Knight, C Prior, Designing substations for offshore connections, connections, offshore for substations CPrior, Designing MKnight, .Finn, Offshore substation platforms substation Offshore E15Appendix – . 5 x17 . allseas . 7 x16m, monopole . . . com/public/2015-0209%20New%20name%20for%20 heerema heerema
(Accessed 08 September 2015) September 08 .(Accessed . . ft allseas . com/cms/s/0/e213d176-ae32-11e4-8d51-00144feab7de . . . . (Accessed: 08 September June 2015) June September 08 .(Accessed: com/content/yards/heerema-zwijndrecht-nl/ com/content/yards/heerema-zwijndrecht-nl/ com/uk/19/equipment/pieter-schelte (Accessed: 08 September 2015)
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Pieter Schelte) Pieter (previously Spirit named Pioneering E15.3 Figure
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Appendix E 49
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. dependent on the harmonic AC filtering needed location particular the at Transmission losses are typically 0 are losses Transmission of transmitted power (per end) (image courtesy of Siemens) Figure E15.1 converter station More Ballycronan Interconnector) (Moyle
. , ‘R&D progress UHVDC of ±1100kV technology’, Paper CIGRÉ B4-201, 2012 . . A CSC , Lu, L . The CSC also . A CSC , ‘Recent evolution in classic HVDC’, (Online), HVDC’, classic in evolution ‘Recent , . . 3 Further development development Further , Zhang, J . , ‘Overview of HVDC CIGRÉ and FACTS’, B4 Colloquium, Bergen, 2009 . . 1,2 , Yu, J . , Yu, , Weimers, L Weimers, , . . . Reactive compensation and Indicative typical dimensions typical dimensions Indicative . 4 . and Zavahir, M , Wang, Z . Appendix E16 – Appendix E16 currentconverters source HVDC: R . , Flisberg, G Flisberg, , . . , Gao, L . Liu, Z L Carlsson, Andersen, B CEPRI, Southern Hami-Zhengzhou ±800kV UHVDC Transmission Project, (Online), (Accessed: July 2015) 22, Siemens, 5000A DC Siemens commutation breaker successfully tested in China, (Online), (Accessed: July 2015) 22, Available: http://www.ptd.siemens.de/141216_Newsletter_5000A_MRTB.pdf Available: Available: http://www.cepri.com.cn/aid/details_72_272.html Available: Because of the commutation process, the converter current lags the phase voltage and the CSC absorbs reactive power generates non-sinusoidal currents and requires requires and currents non-sinusoidal generates filteringAC to avoid exceeding harmonic limits in the network AC harmonicAC filters are therefore provided and account for around 40 60% to of the converter station footprint of this technology is a continual process, a new ultra HVDC (UHVDC) ±1100kV/5000A Zhundong–Chengdu is China in project power electric China the by considered being (CEPRI) research institute 3 4 5 1 2 therefore depends on the voltage of the the of voltage the on depends therefore networkAC which to it is connected for commutation of current in its valves HVDC system is larger and heavier than a voltage source converter (VSC) one so will be more difficultto implement in an offshore location Capabilities CSC HVDC is well suited transmission to of large quantities of power over long distances An installation rated at 8000MW at a voltage of ±800kV using overhead lines was 2014 in commissioned The thyristor can be switched on gate a by signal and continues conduct to until the current through it reaches zero Most of the HVDC the service transmission in Most of systems type. are current the This (CSC) source converter well-established has been technology use since in 1970s. the since valves thyristor using 1950s, the Electricity Statement Year Ten 2015 for a 1000MW CSC located onshore are about but x 22m, the200m footprint x 175m is highly Appendix E 1 to around requirement SCR the reduced have such as capacitor commutated converters valve commutation for AC network strong arelatively require CSCs Dependencies and impacts manufacturing time cable associated by any dominated be may voltage DC the of polarity the in achange requires direction flow power the of Areversal stations. the HVDC connection between the converter to form line overhead or cable impregnated mass with used be can technology CSC commutation valve successful for voltage sufficient to provide compensator (STATCOM) or rotating machine astatic as such source avoltage require would 2 least at be should power, HVDC rated by the divided level fault or power circuit short the as (SCR), defined ratio this can mean a wait before re-starting power power re-starting before await mean can this and are typically 2 typically are and Lead times depend on project requirements such as CEPRI can also offer such products Siemens, although several eastern suppliers Suppliers include ABB, Alstom Grid and Availability 2015 Ten Year Statement Electricity 6 Vancers, I Vancers, during 2005 – 2006’, Paper B4-119, 2008 Paper –2006’, CIGRÉ 2005 during . 0, but in either case to use a CSC offshore offshore aCSC to use case either in 0, but . When using mass impregnated cables, . , Christofersen, D , Christofersen, HVDC: source converters current E16Appendix – . . 5-3 years 5-3 . . . In general, the circuit short 5 Recent developments developments .Recent . J . , Leirbukt, A , Leirbukt, The lead times times lead .The and Bennet, M Bennet, .and .
. G
. , ‘A survey of the reliability of HVDC systems throughout the world world the throughout systems HVDC of reliability the of , ‘A survey CIGRÉ Group Advisory B4 converter the than rather cable the of ratings by the limited be still may capacity transmission ratings than extruded cable, the achievable Although mass impregnated have cables higher required. is flow power of reversal no where used be may cables direction opposite the in transfer first went into operation. into went first they since world the in systems HVDC most for performance reliability of record continuous a provide and outages scheduled and forced contain data on energy availability, energy use, held in Paris every two years two every Paris in held Session CIGRÉ the at results the publishes and systems HVDC of reliability the of survey annual . 04 6 The reports reports .The 5 conducts an Extruded .Extruded .
50 Appendix E
. 51 The . . The . 11 1,2
this 2210km . The project is being com/hq/pool/hq/ . The connection has a has connection The . this link will have an 10 The whole project was was project whole The . 1 . The project is scheduled be to siemens . com/systems/hvdc/references/norned energy . . The converter stations were supplied supplied were stations converter The . abb . executed CEPRI, by China and HVDC and Chinese by supplied were components manufacturers international other commissioned in 2016 executed ABB by . project has a ±800kV voltage rating and will one be will that solution multi-terminal a form of the first of its kind in the world (the others England–Quebec New scheme the being Italy–Corsica–Sardinia HVDC the and (SACOI) link) submarine cablesubmarine 8,000MW converter capacity, including a including capacity, converter 8,000MW 2000MW redundancy, transmit to clean hydroelectric power from the north eastern and eastern regions of India the to city of Agra across a distance of 1,728km North-East Agra transmission capacity of 700MW at a DC voltage of ±450kV and went into operation in 2008 ABBby and the cables ABB by and Nexans Southern Hami – Zhengzhou – Southern Hami region north western in Hami connects link China, middle Zhengzhou, and China of China of provinces six through going link was commissioned in January, 2014 and has a world record 8,000MW converter capacity at a rated DCvoltage/current of ±800kV/5000A n n , ‘Experience feedback on the Cross-Channel 2000MW link . W
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.
. Available: http://www Available:
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. Available: http://new Available: . . The 9 . and Swanson, D R . The link is a . 8 . The link was . The converter . The converter . com/systems/hvdc/references/north-east-agra . . connects the British and British the connects , Monkhouse, D . the link connects the the connects link the abb . the link connects Victoria, on Victoria, connects link the . The link consists of two separate 7 It has a nominal rating of 500MW, 500MW, of rating nominal a has It , Bourgeat, X . . Dutch transmission systems transmission Dutch BritNed the link BritNed the bipoles, each with a transmission capacity transmission a with each bipoles, of 1000MW at a DC voltage of ±270kV monopole a as operate can bipole Each operational allowing 500MW transfer to flexibility. The cross-Channel link went into 1986 in operation the Australian mainland, to George Town, Town, George to mainland, Australian the Tasmania, means by of a circuit comprising underground 8km line, overhead 72km cable 290km submarine and cable Basslink stations were supplied Siemens by and the cables ABB by . commissioned in early 2011 1000MW bipole that operates at ±450kV over a 260kmsubsea cable HVDC cross-Channel link connects link the transmission British and French the systems NorNed HVDC NorNed transmission systems in Norway and the Netherlands means by of a 580km operates at a DC voltage of 400kV and went into operation in 2006 connection is monopolar with a metallic metallic a with monopolar is connection return stations were supplied Siemens by and the Prysmian by cables
ABB, NorNed, (Online), (Accessed: June 26, 2014) 26, June (Accessed: (Online), NorNed, ABB, ABB, North-East Agra, (Online), (Accessed: June 26, 2014) http://new Available: after 20 years of operation’, Paper B4-203, CIGRÉ 2006 Siemens, Basslink, (Online), (Accessed: June 26, 2014) http://www.energy.siemens.com/hq/pool/hq/power-transmission/HVDC/HVDC-Classic/pm-pdf/pm_basslink_neu.pdf Available: Dumas, S 2014) 26, June (Accessed: (Online), BritNed, Siemens, power-transmission/HVDC/HVDC-Classic/pm-pdf/Press_BritNed_2011_04_01_e.pdf n n 9 10 11 7 8 Project examples Project n Electricity Statement Year Ten 2015 n Appendix E 3 2 1 system HVDC VSC bipole a1400MW and 2015 in commission being is system a 2x1000MW transmission system in operation is 864MW HVDC aVSC for capability transmission highest the while and, development significant systems CSC than ratings power and voltage to lower limited been have far so installed systems HVDC VSC The Capabilities technical benefits. solution to VSC installations because of its preferred the become has it and suppliers by most introduced been has principle (MMC) converter multi-level amodular recently, More with pulse width modulation (PWM) switching principles converter three-level or two the use installed systems HVDC VSC the of Most applications system power for advantages systems HVDC VSC give and signal by agate off and on turned gate bipolar transistors (IGBTs), which can be semiconductor devices such as insulated (CSC) technology, it uses self-commutated Unlike the current classical source converter systems late the since 1990s transmission HVDC in used technology been has converter (VSC) power. DC and voltage emerging The source system AC between convert and transmission the form of terminals HVDC an Converters 2015 Ten Year Statement Electricity 7 6 5 4 Skagerrak 4 has been commissioned in 2014 in commissioned been 4has Skagerrak Siemens, Siemens hands over North Sea grid connections to TenneT, (Online), (Accessed: August 17, August 2015) Available: (Accessed: toTenneT, http://www (Online), connections grid Sea North over hands Siemens Siemens, 17,Available: August 2015) http://www (Accessed: (Online), Platform, HVDC SylWin1 Sheet Fact Siemens, B4 Group Working CIGRÉ ABB, NSN, (Online), (Accessed: August 17, 2015) ABB, NordLink, (Online), (Accessed: August 17, 2015) ABB, Skagerrak 4, (Online), (Accessed: August 17, 2015) 17, August Available: 2015) http://www (Accessed: (Online), Interconnector, France-Spain INELFE Siemens, 4 Moreover, a 700MW monopole system – – system monopole a700MW .Moreover, HVDC: voltage source converters voltageHVDC: source E17Appendix – . siemens . . energy siemens However there has been been has there .However . . 37, ‘VSC Transmission’, Ref 37, Transmission’, ‘VSC . siemens . com/press/en/feature/2013/energy/2013-08-x-win . com/press/pool/de/feature/2013/energy/2013-08-x-win/factsheet-sylwin1-e . com/hq/en/power-transmission/hvdc/references . Available: http://new . Available: http://new
269, April 2005 April .269,
2,3, 2,3, . Available: http://new . 5
it is planned Norwegian and GB transmission systems when HVDC submarine connecting cables between the of length the for record aworld have will 2015 in built to be announced been (image courtesy of ABB) of courtesy (image Sea North platform, HVDC BorWin1 E17.1 Figure ±525kV systems –NordLink ±525kV systems becomes technically available: two 1400MW . abb . . abb com/systems/hvdc/references/nsn-link . abb . . com/systems/hvdc/references/nordlink php?content()=WP&content()=PS&content()=EM . . com/systems/hvdc/references/skagerrak .
.
. htm# 6 and NSN and .
The NSN NSN .The 1 . 7 have have 52 Appendix E 53 . . . The
. . Although . However, where extruded extruded where However, . their use is increasing,there is limited performance and reliability the on information cables are used, the achievable transmission transmission achievable the used, are cables capacity may be limited the by ratings of the cable rather than the converter HVDC in technology VSC Experience with systems dates from the late 1990s Dependencies and impacts and Dependencies The ability reverse to power flow without HVDC VSC polarity allows voltage the changing transmission systems use to extruded cables mass alternative the than cheaper are which cables impregnated lead time for a project may be dominated by time manufacturing cable associated any Lead times depend on the requirements of a given project and are typically 2–3 years Figure E17.2 BorWin1 offshore 400MW converter
. . . VSC technology VSCs do not depend depend not do VSCs . . 9 pdf . Indicative typical dimensions typical dimensions Indicative .
. . . 8 et al, “VSC-HVDC Transmission with Cascaded Two-Level Converters”, 2010, CIGRÉ B4-110 CIGRÉ 2010, Converters”, Two-Level Cascaded with Transmission “VSC-HVDC al, et .
It can also provide voltage support voltage provide also can It . . Available: http://www05.abb.com/global/scot/scot221.nsf/veritydisplay/2742b98db321b5bfc1257b26003e7835/$file/ Available: Pow0038%20R7%20LR ABB, ‘It’s time to connect – Technical description of HVDC Light® technology’, (Online), (Accessed: June 17, 2014) 17, June (Accessed: (Online), technology’, Light® HVDC of description Technical – connect to time ‘It’s ABB, B Jacobson, 8 9 Since the power flow is reversed without voltage, DC the polarity of the changing and since the IGBT valves do no suffer is, technology VSC failures, commutation multi-terminal to suited well principle, in applications offshore an where solution practical a is VSC wind farm requires an HVDC connection Availability Alstom and Siemens ABB, include Suppliers Grid, with other potential eastern world solutions VSC deliver to able also suppliers VSCs can meet the requirements of the code owner transmission – operator system reactive including point interface the at ride fault control, voltage capability, power through capability, operation over a range of oscillation power provide can and frequencies damping VSCs can generate or absorb reactive power and allow active and reactive power be to independently controlled A VSC has a smaller footprint than a CSC with ratings equivalent on the presence of a synchronous voltage AC for their operation and may be used feed to weak or passivenetworks AC can restart dead a network AC if there is a blackout operation) to (static compensator (STATCOM) a local network AC if there is a fault or during instability system for a 1000MW VSC located onshore are 90m x 54m x 24m Electricity Statement Year Ten 2015 Converter losses are approximately of 1% transmitted power (per end) for a MMC-based station converter HVDC Appendix E n n Project Examples 2015 Ten Year Statement Electricity 11 10 Available: http://www 17, June 2014) (Accessed: (Online), Project’, MTDC Nan’ao RXPE, Available: http://new 17, June 2014) (Accessed: (Online), Light, HVDC BorWin1 ABB, ±320kV of voltage aDC at operate will bipoles both 2GW and be will capacity power total atunnel in and trenches in cables distance of about 65km with underground 1GW bipole HVDC links with a transmission systems transmission Spanish and French the interconnect will that project interconnector an is project this INELFE Interconnector France-Spain in 2015 in offshore wind farm connection an to technology HVDC of application first the is project .The by ABB supplied were 2012 ±150kV and has been commissioned in of voltage aDC at 400MW of capacity cables HVDC circuit comprising submarine and land a125km of by means system transmission German to the farm 1wind offshore BorWin1 The converter stations and cables cables and stations converter .The 10 4 . . . The link is being commissioned HVDC: voltage source converters voltageHVDC: source E17Appendix – The connection has a transmission the project connects the BARD BARD the connects project the . abb . rxpe . com/systems/hvdc/references/borwin1 . co . It consists of two two of consists .It uk/index . php?m=content&c=index&a=show&catid=1&id=30 . The .The
.
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offshore wind farm connection an for system VSC largest world’s the is 2015 currently June and since operation The connection has been in commercial The converters are supplied by Siemens ±320kV2 of voltage aDC at 864MW of connection has a transmission capacity 205km of length atotal with cables submarine/land HVDC of by means system transmission German to the farm Tysk wind SylWin1 length of 32km of length total with cables land/sea lines, overhead DC Guangdong Province through a mixture of of AC networks to mainland Nan’ao Island to bring dispersed wind power generated on Guangdong Province of China with the aim Nan’ao on Island, situated is project This project. HVDC VSC multi-terminal first 2013 world’s the as December since respectively 200/100/50MW of ratings ±160kV power and of voltage DC rated with project HVDC VSC athree-terminal system, transmission Multi-terminal HVDC Project in China’s the project connects the Dan Dan the connects project the . It has been put into operation 11 . 3 . Nan’ao Nan’ao The .The .
. 54 Appendix E 55 Figure E18.1 (image courtesy of Prysmian)
.
. . XLPE-insulated cables cables XLPE-insulated . In deeper waters, . . . . This allows them carry to more . The table below gives an example . The armour is usually a single layer layer single a usually is armour The Appendix E18 – Appendix E18 extrudedcables HVDC: . . This sheath is usually made of extruded . Submarine cables usually use copper as are generally mechanically robust and they they and robust mechanically generally are may operate at higher temperatures (70˚C) than polypropylene- from (aside designs cable MI laminated MI) current for a given conductor cross section A further protective polyethylene plastic coating coating plastic polyethylene further protective A design the completes Extruded XLPE insulation is a relatively new entry the to HVDC cable market, which up until now has been dominated mass by cables (MI) impregnated an has use submarine for intended Cable additional layer of galvanised steel wire armour The plastic insulation is extruded over a copper a over extruded is insulation plastic The lower a has (copper conductor aluminium or resistance and thus a higher power density, expensive more and heavier is it although watertight a with covered and aluminium) than sheath seamless lead for submarine cables, or of cables land for laminate aluminium welded Most extruded HVDC cables use cross-linked Other (XLPE) types insulation. their for ofpolyethylene beenplastic developed. materials insulation have of wires wound around the cable, covered in a polypropylene bitumen-impregnated serving of yarn reduce to corrosion Capabilities Extruded HVDC cables are available in voltages up 525kV to This increases its tensile strength so it can better withstand the stresses of submarine installation or over rocky seabeds, a double layer may be used for used often is aluminium while conductor, the cablesland of cable systems for the stated power transfers, although actual cable system designs will vary from project project to Electricity Statement Year Ten 2015 Appendix E Ratings calculated from IEC 60287 IEC from calculated Ratings 200m of adepth at deployed successfully been have cables XLPE Subsea 1 60287 IEC from calculated Ratings cable asingle of that twice is weight bundle cable; asingle for given are characteristics wire armour, bipole laid as bundle round 1kW/m, steel 4mm resistivity thermal 1.0m, 15˚C, burial temperature Ground/seabed above table: The following assumptions were made for the E18.1 Table 2015 Ten Year Statement Electricity 3 2 capacity capacity International Electrotechnical Committee, IEC 60287: Electric Cables – Calculation of the Current Rating, 1995 ABB, White paper, The new 525kV extruded HVDC cable system (online) system cable HVDC extruded 525kV new The paper, White ABB, Available: http://global-sei (online) System Cable DC-XLPE Voltage High of Development J Power, new%20525%20kV%20extruded%20HVDC%20cable%20system%20White%20PaperFINAL Available: http://www05.abb.com/global/scot/scot221.nsf/veritydisplay/7caadd110d270de5c1257d3b002ff3ee/$file/The%20 Bipole Bipole (MW) 1000 800 600 500 400 300 200 HVDC: cables extruded E18Appendix – Voltage (+/-kV) 320 320 200 320 200 150 320 200 150 320 200 150 320 200 150 200 150 . com/technology/tr/bn76/pdf/76-09 section Cross (mm²) 1,600 1,000 2,200 1,400 2,200 1,000 1,800 1,200 630 500 300 630 185 400 630 185 400 . Typical submarinecable . Physical 1 1 Cu conductor . . Weight (kg/m) 41 33 46 24 36 44 22 29 39 19 22 29 17 19 21 15 17 .
. pdf Diameter designed at 500kV available for some time manufacturers have had cable systems 300kV of excess in products Several manufacturers are developing power transfer agiven for section cross conductor reduced thermally independentwould result in a are they that so separately cables Laying qualification tests at 525kV tests qualification has recently announced the completion of pre- supplier cable European first The consortium. by aEuropean bought been just has 400kV at cable pre-qualified recently the and (mm) 116 107 120 108 112 105 97 94 99 88 91 96 84 85 85 78 79 Accessed 9 September 2015) 9 September .Accessed (Accessed 9 September 2015) 9September .(Accessed section Cross (mm²) . 2,400 1,600 1,000 2,000 1,600 2,400 1,000 1,600 1,000 N/A N/A 630 500 300 630 300 500 Typical landcable . pdf Al conductor Weight (kg/m) 3 . N/A N/A . Far East East .Far 14 11 12 10 12
9 9 6 8 9 5 6 7 5 5 .
.
Diameter
(mm) 105 N/A N/A 94 85 94 93 88 93 71 79 82 68 71 73 62 62 2
56 Appendix E 57
. . Some suppliers Some . 4 For long submarine submarine long For . This means a higher . . This means they’re likely
. XLPE cable joints are pre-fabricated pre-fabricated are joints cable XLPE . are testing extruded cables meet to CIGRÉ requirements test LCC-type only used with voltage source converter (VSC) HVDC systems due the to risk polarity reversal voltage by represented and space charge effects to beto less expensive. This has benefits for land lengths drum individual where applications are shorter and there are a correspondingly joints of number higher extrusion manufacturing the connections, cable lengths of the XLPE cable are shorter than that for similar MI cable number of factory joints arenecessary theAt moment, XLPE extruded cables are Dependencies and impacts and Dependencies minimal is there insulation, plastic all With environmental impact in the case of external damage and so need less time per joint than that required for MI cables
. . . The Prysmian and Nexans Nexans and Prysmian The . . . Electric Power Research Institute, DC Cable Systems with International Extruded Consulting Cable by Compiled Dielectric, Dec 2004 4 Availability Suppliers: the ABB cable factory in Karlskrona, Sweden is being expanded accommodate to cables submarine of manufacture the Meanwhile, the Prysmian cable factory factory cable Prysmian the Meanwhile, supply to expanded being is Italy Naples, in the submarine DC cable for the offshore wind market farm facilities are in South Carolina and focused on and underground extruded of production the submarine cables; while ABB has recently sold its North Carolina factory, which focused on cables underground DC and AC EHV on depend times installation and Supply the length of cable required, and the design already necessary an testing (using and proven cable design removes the development lead time), but are generally in the range yearsof 2-3 In the US, manufacturing capability has manufacturing US, the In increased with recent investment in factories by Suppliers European Electricity Statement Year Ten 2015 Appendix E 10 9 8 7 6 5 n Project examples – Commissioned 2015 Ten Year Statement Electricity 11 n n n Prysmian, HVDC Cable System for Land Transmission (online) ABB, East-West Interconnector: connecting Ireland and Britain (online) (online) –BorWin1 farms wind offshore of connection Grid ABB, power_cable_contract.html Available: http://www.nexans.no/eservice/Norway-no_NO/navigatepub_142647_-3665/Nexans_wins_98_million_subsea_ (online) project Shore from Power September Valhall BP’s for 2015) contract cable power subsea million €98 wins Nexans Nexans, (online) US the –Interconnecting Bay Cable Trans Prysmian, Available: http://new Available: http://new Available: http://prysmiangroup.com/en/corporate/about/special_projects/trans-bay/ J Power, J-Power wins contract with NEMO LINK for HVDC Subsea Interconnector Cable system between UK and Belgium and UK between system Cable (online) Interconnector Subsea HVDC for LINK NEMO with contract wins J-Power J Power, Available: http://www ABB, DolWin1 – Further Achievements in HVDC Offshore Connections (online) DolWin1%20further%20achievements%20in%20HVDC%20offshore%20connections Available: http://www05.abb.com/global/scot/scot221.nsf/veritydisplay/0817901b2514978ec1257c3000435c3a/$file/ supplied by Prysmian cable submarine DC 2x80km cables, DC, bipole, 5km underground AC and DC 400MW, (2010): Cable Bay Trans ±200kV Nexans 292km DC submarine cable supplied by (2011):Valhall 78MW, 150kV DC, monopole, cables are supplied by ABB supplied are cables 39kg/m) (1,650mm² CU, 117mmcable diameter, 12kg/m),diameter, submarine DC 2x186km (2,210mm² 107mm AI, cable underground DC 2x75km DC, bipole, ±200kV 500MW, East West Interconnector (2013) underground are cables supplied by ABB 29kg/m) diameter, (1,200mm² CU, 98mm cable submarine 11kg/m), diameter, 96mm 2x125km DC AI, (2,300mm² cable underground DC ±150kV 2x75km 400MW, DC, bipole, (2012): Farm Wind Offshore BorWin1 (Accessed 9 September 2015) 9September .(Accessed 6 . HVDC: cables extruded E18Appendix – . Submarine and underground .
. . abb abb . jpowers . . com/systems/hvdc/references/east-west-interconnector com/systems/hvdc/references/borwin1 The DC submarine and and submarine DC .The 5 . co . . jp/pr/150608/150608e 8 . .
:
7 . . pdf (Accessed: 9 September 2015) 9September .(Accessed:
. (Accessed: 9 September 2015) 9September .(Accessed: n n n construction –Under examples Project supplied by Prysmian CU, 128mm 34kg/m) diameter, (2,500mm² route land DC 4x64km ±320kV, 2xbipole, INELFE, France-Spain: 1,600mm² CU, 125mm1,600mm² 44kg/m) diameter, CU, 115mm1,000mm² 2) 34kg/m; diameter, cable submarine DC 2 x75km CU, 114mm1,600mm² 33kg/m). diameter, 118mm AI, 2,000mm² 14kg/m; diameter, 2) cable underground DC 2x90km DC, bipole, ±300kV 800MW, Farm: Wind Offshore DolWin1 commissioned in 2015 . Japan of by J-Power supplied 142km length, route NEMO LINK: 1000MW, ±400kV DC Bipole recently been commissioned has project .This by ABB supplied are The DC submarine and underground cables . (Accessed: 9 September 2015) . (Accessed: 9 September 2015) 11 . pdf .
Two types of cable: 1) cable: of .Two types
.
9
This project was was project .This . 2x1,000MW, .
. Two types: 1) .Two types: .
(Accessed: 9 9 .(Accessed: 10
.
58
. Appendix E
59
.
The following following The . 2
. . 1 . 485) . No They are available up to voltages voltages to up available are They . . Publ A dual concentric conductor design allows allows design conductor concentric dual A following capability transmission power some on operation (monopolar fault cable single a albeit conductor), return a with cable single a reduced a at rating are some cable specifications for particular projects: of 600kV and ratings of 2,500MW per bipole Capabilities MI HVDC cables are usually designed and manufactured according specific to project requirements The maximum contracted rating is now 600kV on a single cable (2225MW/ and 1110MW Link Western the for bipole) Figure E19.1 Neptune 500kV bundle (lightly insulated XLPE return cable is shown on the right, smaller fibre optic communications cable in the centre) (image courtesy of Prysmian)
.
.
. The sheath sheath The . . Voltage levels levels Voltage . . Polypropylene Polypropylene . , The Moyle HVDC Interconnector: project considerations, design and implementation, implementation, and design considerations, project Interconnector: HVDC Moyle The , . . . Seventh International Conference on (Conf . In deeper waters,
Wohlmuth, M Wohlmuth, . . . The armour is usually a single layer layer single a usually is armour The HVDC: submarineHVDC: – E19 Appendix cables mass impregnated . Stenseth, K Stenseth, . . Submarine cables usually use copper as Harvey, C Harvey, Aspects, Environmental Repair, Installation, Design, Cables: Power Submarine Worzyk, Thomas AC-DC Power Transmission, 2001 Published 2009 ISBN 978-3-642-01270-9 1 2 Cable intended for submarine use has an has use submarine for intended Cable additional layer of galvanised steel wire armour and VSC converter technologies converter VSC and For both land and submarine cables, the insulation is surrounded a lead by sheath This adds mechanical strength and protects damage water from insulation the is then covered with a plastic coating that corrosion reduces They allow very high power transfers per cable and are suitable for use with both CSC laminated paper designs (PPLP), with the to temperatures operating increase to potential 85˚C for very high power applications, exist, but have not been commissioned yet HVDC mass cable (MI) impregnated systems of wires wound around the cable, covered in a polypropylene bitumen-impregnated serving of yarn reduce to corrosion are a mature technology (in use since the 1950s) are 1950s) (in the use since technology a mature record reliability high of and anwith excellent performance. are now approaching 600kV The conductor is usually copper due the to permitted are cables these temperature lower operateto at (55˚C), but may also be aluminium. The insulation is made from layers of high- papers oil-impregnated density, This increases its tensile strength, so it can better withstand the stresses of submarine installation or over rocky seabed, a double layer may be used conductor the designs system cable HVDC Conventional conductor concentric single use to tend designs in a range of configurations, depending on the return current arrangements Electricity Statement Year Ten 2015 Appendix E 3 years 2–4 of range the in generally are but time), lead development the removes design cable proven and (using testing an necessary already design the and required, cable of length the Supply and installation times depend on than extruded XLPE cables consuming and expensive to manufacture Norway) Halden, in factory (cable Nexans and Italy) Naples, in factory (cable Prysmian Sweden), Suppliers: ABB (cable factory in Karlskrona, Availability to 1,650m up of depths water at installed carry can drum cable or weight of cable that the transportation vessel can be manufactured, the limitation being the Cable lengths of several hundred kilometres E19.1 Table 2015 Ten Year Statement Electricity 5 4 to 60kg/m with diameters of 110 of diameters to with 140mm to 60kg/m 30 are cable core asingle for weights Typical ABB, BritNed – interconnecting the Netherlands and U and Netherlands the –interconnecting BritNed ABB, J .E Available: https://library ABB, The NorNed HVDC Connection, Norway – Netherlands (online) DC%20MI%20sub Available: https://library MI%20subm-land%20rev%204 DC voltage Core type Core area Capacity Project Weight Skog, Statnett SF, NorNed – Innovative Use of Proven Technology, Paper 302, CIGRE SC B4 2009 Bergen Colloqium Bergen 2009 B4 SC CIGRE 302, Paper Technology, Proven of Use –Innovative SF, NorNed Statnett .Skog, Type MI cable is more complex, time time complex, more is cable .MI . mass impregnatedmass cables Appendix E19 –HVDC: submarine . pdf single core in deep water Two core + . . NorNed e e 790mm² . . 700MW 84kg/m abb abb 450kV Bipole . . com/public/2402665447f2d054c12571fb00333968/Project%20NorNed%20450%20kV%20 com/public/1efa2a0680f6b39ec125777c003276c9/Project%20BritNed%20450%20kV%20 MI cable has been been has cable .MI . pdf . 3,4 Single core 1,430mm² 1,000MW BritNed 44kg/m 450kV Bipole
. 6
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K
. 6 power grids (online) grids .power 5
HVDC MI cables MI HVDC with factories capable of manufacturing suppliers European three only are There transportable lengths will not differ by much that so cables, MI than larger physically be to tend rating equivalent of cables XLPE but cables, XLPE than more weigh cables MI conductors have been let land MI of to 90km up with projects although to 320kV, up voltages HVDC of range the in cable less competitive for onshore application this makes which expensive, hence and each) days (3–5 make and to prepare consuming Where required, cable joints are time Dependencies and impacts 750MW peak 600MW cont Single core 2,100mm² Monopole Neptune 53 .5kg/m . + return (Accessed: 11 September 2015) 500kV (Accessed: 10 September 2015) 10 September .(Accessed: 6 . (deep waters) 1,150mm² Al waters) and Cu (shallow emergency Single core 1,000mm² 1,000MW Bipole + 37kg/m SAPEI 500kV return . 6 .
Bass Link Single core . 1,500mm² Monopole
500MW + return 43kg/m 400kV
. . 6 60 Appendix E 61
. This 11 .
.
12 . 9kg/m) . 6 .
. and other 92km DC . 10 000MW, ±500kV bipole, DC, . The cable is a 1,000mm² 8 140km DC submarine cable submarine DC 140km . 9 . 5mm diameter, 34 .
. Commissioning 2017 Commissioning project has recently been commissioned been recently has project Western Link: 2200MW 600kV DC bipole, route-km420 which (of 38km is on land) beto provided Prysmian by and 12km DC underground cable route are are route cable underground DC 12km and provided by Nexans underground cable Prysmian by (1,600mm² 111 CU, SAPEI (2011): 1 SAPEI (2011): 500kVSkagerrak 140km DC, 715MW, 4: land 104km and route cable submarine route cable 420 km DC submarine cable route supplied route cable submarine DC km 420 Prysmian by copper conductor for the low-medium water water low-medium the for conductor copper depth portion (max 400 and m) 1,150mm² water high the for conductor aluminium depth part 1,650m) (up to . (Accessed: September 11 2015) Project examples – Under construction n n n .
6
.
.
7 . . (Accessed: September 11 2015) . Pozzati, Challenges and Achievements For New HVDC Cable Connections, Paper 502, . For DC submarine
6 . The cable is a . . 3 . The cable is supplied com/systems/hvdc/references/skagerrak . . (Accessed: September 11 2015) . Miramonti, G abb . 290km DC submarine cable submarine 290km DC . . Orini, G in two continuous lengths of 100km, so only one joint is required offshore Fenno-Skan 2 (2011): 800MW, 500kVFenno-Skan 2 (2011): 200kmDC, of DC submarine cable route supplied Nexans by cable route, two types of cable supplied by ABB: 2 x 150km single-core cable, 700mm² 2 x 790mm² 84kg/m. is supplied Prysmian by 1,500mm² conductor plus metallic return and fibre optic, 60kg/m. bipole, DC, ±450kV 700MW, (2008): NorNed 580km total route length 270km twin-coreCU 37kg/m; flat cable, Basslink (2006): 500MW, 400kV DC, monopole . Marelli, A Nexans, Nexans wins million 87 Euro contract for Skagerrak 4 subsea HVDCpress power release, cable between 7 January (online) Denmark 2011 and Norway, http://www.nexans.com/Corporate/2011/Skagerrak4_GB.pdf Available: Prysmian Group, Prysmian secures the highest value cable project ever awarded, worth €800 million (online) million €800 worth awarded, ever project cable value highest the secures Prysmian Group, Prysmian http://investoren.prysmian.com/phoenix.zhtml?c=211070&p=RssLanding_pf&cat=news&id=1661739 Available: (Accessed: September 10 2015) Prysmian, HVDC Cable Systems for Land Transmission (online) Transmission Land for Systems Cable HVDC Prysmian, Available: http://new Available: ABB, Skagerrak 4 – Excellence Benefits through Interconnections(online). (Accessed:11 September 2015). Available: http://prysmiangroup.com/en/corporate/about/special_projects/SAPEI-connect/ Available: Available: http://www.nexans.com/Corporate/2008/Nexans_Fenno_Skan%202_GB_1.pdf Available: Prysmian, SAPEI – Connecting Sardiniathe to Italy Mainland (online) M Nexans, Nexans wins million 150 Euro submarine power cable contract to interconnect Finland and Sweden, Press Release, 19 March19 2008 (online) CIGRÉ SC B4 2009 Bergen Colloqium n 11 12 8 9 10 6 7 n Project examples – Commissioned – examples Project n Due the to high viscosity of the oil, MI cablesdo not leak oil into theenvironment if damaged There are not thought be to significant differences in the robustness of XLPE or MI levels similar need which of both insulation, of care during installation during care of Electricity Statement Year Ten 2015 Appendix E 1 heat dissipation and insulation for air on rely lines Overhead of comparable capacity circuits line AC of overhead lines) and towers for (area requirement land the of two-thirds about AC circuit adouble for conductors six or AC circuit single a for conductors to three compared bipole, a for conductors two carries tower A DC design insulation the and requirements field electric the conductors, the of configuration the are lines DC AC and between differences main The for onland. use to AC overhead cables, HVDC and lines cables, and over alternative onshore. an They long distances are of power quantities voltages DC large at highest the overheadHVDC to beused lines transmit can 2015 Ten Year Statement Electricity 3 2 over. to flash insulation the cause can as salt deposits, on the surface of the insulator long creepage path because pollution, such a to have is design insulator of requirements tower steel the of body the Insulators separate the conductors from cables for those than shorter much generally are lines overhead for constants time Guide for the Selection of Insulators in Respect of Polluted Conditions, 2008 International Electrotechnical Committee, IEC 60815 – Transmission, HVDC for Lines Electrical Performance of Overhead HVDC Transmission Book: Lines, June 2008 Reference HVDC EPRI Institute, Research Power Electric Available: http://www 2014). June 10 (Accessed: (online). Intertie HVDC Pacific ABB, .
. HVDC overhead line circuits take up HVDC: overheadHVDC: lines E20 – Appendix . This means that the thermal . abb . co . uk/industries/ap/db0003db004333/95f257d2f5497e66c125774b0028f167 .
One of the main main the of .One .
for DC insulators industry hasindustry also fallen heavy of level the because falling been have In the UK, pollution levels outside coastal areas highly polluted environments, may be favoured in effectively more perform which insulators, (photo courtesy of Siemens) of courtesy (photo link 300kV tower Bipolar Figure E20.1 paths (43 paths they need to be designed with longer creepage means This field. electric DC constant by the caused attraction of electrostatic the because DC insulators have more contamination heavy pollutionheavy levels . 3kV/mm for AC insulators under under AC insulators 3kV/mm for 2,3 ) . As a result, polymeric 1 relative to 53-59kV/mm relative . . aspx
62 .
Appendix E . 63
7 6 . . .
. 5 . aspx . aspx . uk/ 1 . .
. As HVDC bipolar . co .
. Commissioned in Commissioned . aspx . 8 beaulydenny . . . It will be the world’s longest
. (Accessed: September 16 2014) 4 .
August 2014 August Xiangjiaba, Shanghai: 800kV HVDC, 800kV HVDC, Shanghai: Xiangjiaba, using bipole overhead 2,071km 6,400MW, steel core6 × ACSR-720/50 conductors North East (India) – Agra: 800kV HVDC, bipole multi-terminal 1,728km 8,000MW, Rio Madeira Brazil: 600kV HVDC, 3,150MW, 2,500km link transmission Caprivi Link: 300kV VSC HVDC, 300MW, 300MW, HVDC, 300kV VSC Link: Caprivi to (potential monopole overhead 970km upgrade 2 x 300MW to bipole) Pacific DC Intertie: 500kV HVDC,3.1GW, bipole overhead 1362km
. . (Accessed: June 10 2014) n n n n The installation of overhead line circuits is circuits line overhead of installation The installation the than disruptive less potentially construction of demands the where cables, of at ground level can lead road to closures and periods long for diversions for consent planning achieving However, challenging, more be can routes line overhead as the recent Beauly-Denny public inquiry documents (consultation demonstrated has available) Overhead lines are less costlythan underground cables and may be able follow to shorter, more direct routes overhead lines only need two conductors, the the conductors, two need only lines overhead transmission towers are simpler in design and shorter in height than the three-phase HVAC towers of equal capacity and comparable more prove may which levels, voltage perspective planning a from acceptable examples Project n . Available:http://www . . There 2 . . . (Accessed: June 10 2014) . (Accessed: June 10 2014) uk/industries/ap/db0003db004333/86144ba5ad4bd540c12577490030e833 uk/industries/ap/db0003db004333/9716a8ac9879236bc125785200694f18 . . co co com/cawp/seitp202/66fa88354c097222c1257d410038c822 . . . . No HVDC overhead lines abb abb abb . . . . . In this case,the availability of HVDC . At 500kV, . At transfers of 4GW are possible 4GW Available: http://www Available: Available: http://www Available: http://www Available: ABB, North East – Agra (HVDC Reference Projects in Asia) (online) ABB, Rio Madeira, Brazil (HVDC Reference Projects in South America) (online) Beauly Denny Public Inquiry (online) ABB, Caprivi Link Interconnector (online) PacRim Engineering, 800KV HIGH VOLTAGE DC (HVDC) TRANSMISSION LINE PROJECT FROM XIANGJIABA TO SHANGHAI TO XIANGJIABA FROM PROJECT LINE TRANSMISSION (HVDC) DC VOLTAGE 800KV HIGH Engineering, PacRim 6 7 8 4 5 Capabilities involves line overhead an of construction The conductors, towers, footings, foundations, the earthing conductor(s) protection lightning (shield wires) and fittings such as insulators, spacers, dampers and surge arresters have been built in the UK date to are similar planning, easement, access and cables, for considerations compensation land and aesthetics are taken into account too Due the to potentially high voltage and current ratings of HVDC lines, power transfer the by dictated usually capabilities are converter station equipment at either end of the route transfers 800kV allows while bipole, single a on of 6 . HVDC overhead lines may operate as a line pole single a of event the in monopole fault, provided an earth return path is in place (the earth wire must be lightly insulated, for instance) Availability There are several distinct components to civil as such construction, line overhead works, tower steel fabrication, insulators, and these for suppliers specialist and conductor individual elements impacts and Dependencies Overhead lines have a greater visual impact audible generate cables and underground than weather fair in particularly noise, lines is expected be to similar double to circuit AC lines Electricity Statement Year Ten 2015 Appendix E 5 4 3 2 1 2015 Ten Year Statement Electricity 8 7 6 following makes afault. This also maintenance easier. HVDC the system functions related to re-configuring anumber of to converter in HVDC order perform an of side Switching DC the provided on devices are demonstrated at laboratory level at laboratory demonstrated available at the moment, but devices have been commercially not are breakers circuit line HVDC available insulated HVDC switchgear is becoming applications where space is limited, gas with appropriate ratings may be used Standard air insulated AC switching devices disconnectors switches and earthing switches, commutating current device: switching HVDC of types three are There although they won’t feature in every scheme 1, in 2, 3, described are functions various The ept201408064 CIGRÉ WG B4 WG CIGRÉ UK 2015, Birmingham, 10–12 February Transmission, power DC AC and on Conference 11thInternational applications’, HVDC for breakers circuit ‘HVDC H, Ito, Y, and R, D, Kono, Yamamoto, Yoshida, K, Kamei, K, Tahata, UK 2015, Birmingham, 10–12 February Transmission, Power DC AC and on Conference DC 11th meshed for networks’, International breaker circuit HVDC J-P, ‘A ultra-fast new Dupraz, CD, and Barker, RS, CC, Whitehouse, Davidson, 2012 Nov Paper, Technical ‘The hybrid HVDC breaker; an innovation breakthrough enabling reliable HVDC grids’, ABB Grid Systems, Available: http://www (online). transmission’, 2015) current 24 August direct for (Accessed switchgear 320kV insulated gas first presents ‘Siemens Siemens, 21-30 pp 1980, Jan 68, No Electra 13 WG CIGRÉ 13/14 WG CIGRÉ 13/14 WG CIGRÉ part 2: disconnectors and earthing switches’, Electra No Electra switches’, earthing and 2: disconnectors part No Electra switches’, commutation 1: current part . 4 HVDC: switchgear E21Appendix – . . . 03, ‘The metallic return transfer breaker in high voltage direct current transmission’, transmission’, current direct voltage high in breaker transfer return metallic ‘The 03, 52, ‘HVDC Grid Feasibility Study’, Apr 2013, pp 38–44, 77–83, Appendix H Appendix 77–83, 2013, 38–44, pp Apr Study’, Feasibility Grid 52, ‘HVDC htm&content()=ET&content()=EM . . 08, ‘Switching devices other than circuit-breakers for HVDC systems, systems, HVDC for circuit-breakers than other devices ‘Switching 08, systems, HVDC for circuit-breakers than other devices ‘Switching 08, . siemens .
. com/press/en/pressrelease/?press=/en/pressrelease/2014/energy/power-transmission/ . 5,6,7 . .
For 125, Jul 1989, pp 41-55 .125, pp 1989, Jul 135, Apr 1991, .135, 32-53 Apr pp .
described in 8 in described availability of HVDC line circuit breakers is the to asurvey, responses manufacturers’ Siemens and Grid Alstom ABB, station converter the of part as supplied is switchgear HVDC The Availability 8 5, 6, 7and in described are breakers circuit line HVDC prototype of 3 in described is breaker transfer switches in 2 1 in current commutation switches are described The function, mode of operation and duties of Capabilities and those of disconnectors and earthing . Operation of the metallic return .
Suppliers include include .Suppliers
.
Based on on .Based Capabilities .Capabilities 64 Appendix E 65 Figure E21.1 Figure Example of HVDC switchgear configuration
. . Dependencies and impacts and Dependencies circuit line HVDC of availability future The HVDC support will multi-terminal breakers systems allowing by a fault on the DC side examples Project DC use schemes HVDC bipolar Many bipolar between switch to switchgear to beto cleared withouttripping the entire system HVDC operation monopolar and Electricity Statement Year Ten 2015 Appendix E The key is shown below shown keyis The cell by acolour-coded indicated is year agiven in capability agiven with technology year against tabulated is key technology areas, in which capability these of each for presented are Matrices years coming in develop anticipates how key technologies might breaker circuit HVDC the as too, such emerging are devices New (MI PPL) insulation technologies impregnated polypropylene paper laminate introduction of extruded and mass in the area of DC cables, including the place taken have developments Significant increasing power transfer capabilities then has been characterised by continuously technology was introduced in 1997 and since HVDC (VSC) converter sourced Voltage wider worksstrategic new developing are and rapidly. Many of the for technologies offshore required 2015 Ten Year Statement Electricity appropriate time the at placed to be have will acontract service, service technology becoming available and being in between elapse would years four typically of for HVDC schemes are such that a period It has been assumed that project timescales commercially available, but not yet in service to be and developed been to have expected is service; amber indicates that the technology available and the time by which it might be in at which a technology becomes commercially time the between to distinguish important is It year that in the technology is not expected to be available It is clear that, for technology to be in in to be technology for that, clear is .It . for offshore strategic optioneering strategic for offshore E22 –Technology Appendix availability . Red indicates that that indicates .Red The availability of of availability .The . This section section .This .
. .
.
or confirmed by manufacturers. by confirmed or endorsed been not has and estimates best Grid’s National represents information The years earlier the in particularly willrisk management still be required, experience will be available, but appropriate of level agreater cell, by agreen indicated experience service of lack the of account takes that approach will require an appropriate risk-managed indicated by an amber cell, its introduction Where the availability of a technology is placed been to have known contracts of basis the on service, in to be scheduled or service, in is technology the that indicates Green placed been has acontract year, provided agiven in service in to be technology the for indicate that it would be possible, in principle, to used is hatching green Consequently, Amber Green Green Red not in service in not Technology available but Technology not available scheduled to be in service or service in Technology to contract subject service in Technology potentially . Where the availability is . .
66 . Appendix E 67 G G G 2035
G G G 2030 .
G G G . 2025 Achievement Achievement 4 . G G G . 2024 . current of more than c . G G G 2023 No figure is given in the present 5 . IGBT modules permitting DC currents currents permitting DC modules IGBT 3 . G G G 2022 The Caithness Moray HVDC Link will have a power rating of 1200MW at ±320kV, representing a d of 2,000A are expected be to available for contracts placed in 2016 Current sourced converter (CSC) technology technology (CSC) converter sourced Current has developed a stage to where it could match the voltage and current ratings of any cable or on used be might it which with line overhead system transmission GB the Zhengzhou – Hami Southern the example, For ±800kV at operates China in link HVDC DC and with a power transfer capability of 8,000MW of higher DC currents may be possible in future years with further development of but materials, and devices semiconductor able cables of availability the on depend would carryto these levels of current 1875A document illustrate to the future development of CSC HVDC converter technology as it is capability the on limit the represent to unlikely of the systemin which it is used within the GB system transmission G G G 2021
. It is A G G
2020 , which uses which , 1 A A G 2019 Current Current . , commissioning, . A A 2 G 2018
The interconnection interconnection The . . A A G Technology potentially in service subject to contract to service subject in potentially Technology service in be to scheduled service or in Technology Technology not available not Technology service in not but available Technology 2017 A R G . 2016 .1 . The highest DC voltage for a VSC HVDC Key 1875 A 1563 A 2000 A 2000 in 2015, comprisesin 2015, two HVDC links with a power transfer capacity of 1,000MW each and representingoperating DC current a ±320kV, at of more than 1,563A Footnotes: see pages 78–79 Table E22.1 Table Voltage sourced converters Where used with a DC cable circuit, the the for capability transfer power achievable converters will depend on the level of DC cable the by permitted voltage of VSC HVDC technology is illustrated in Table E22 by scalable are converters multi-level modular voltage and could reach the DC voltage level of development little with cable foreseeable any effort system presently in service is 500kV pole-to- ground for the Skagerrak 4 project HVDC converters HVDC capability the in development expected The E22.1 – Technology availability (components) availability – Technology E22.1 Electricity Statement Year Ten 2015 assumed that converters will continue reach to the level of DC voltage permitted the by cables develops technology the as between France and Spain MI cables and became operational in 2015 The level of DC current achievable is determined the by IGBT modules used in valves converter the Appendix E extruded DC cable system has been qualified. been has system cable DC extruded for the Nemo Link interconnector 400kV is order on currently cables extruded the next 2-3 years next the in available be would cables extruded 500kV that view the expressed SKM 2013, June in published report review their In plans to their regard with cautious more and specific less to be tended but developments, Other manufacturers were also pursuing Japan in developed been has 500kV of voltage aDC with cable extruded that stated another 10 to 15 within 750kV years; and 5 years of would 600kV be available within the next voltage aDC for cables extruded that indicated in Tablein E22 illustrated is insulation PPL MI and MI with The expected availability of HVDC cables timescales for development and testing likely the of ajudgement with together cables extruded of development the for forecasts of Table E22 to cable manufacturers sent been had that aquestionnaire of results Ref CIGRÉ the development, to cable regard With service in are 320kV of voltage aDC with cables Extruded Table in E22 illustrated is insulation extruded The expected availability of HVDC cables with HVDC cables 2015 Ten Year Statement Electricity Footnotes: see pages 78–79 pages see Footnotes: 533 published in April 2013 included the the 2013 included April in published .533 . 2 takes into consideration the range range the consideration into 2 takes for offshore strategic optioneering strategic for offshore E22 –Technology Appendix availability . 3 . 6 . The highest DC voltage for . 4 . 9 One respondent . 7 A 525kV 525kV A
.
. . 2
. 8 .
cable installation difficult more of cost the at increased be because the conductor cross section could limit afundamental represent not does This with the results of the CIGRÉ Ref CIGRÉ the of results the with be challenging but possible would years early the in to 2,000A capability development, an increase in current-carrying Sardinia and Italy between link HVDC SAPEI the on service in present at voltages higher achieve can and cables extruded than established more are cables MI service in 2017 in service to enter scheduled Link, HVDC Western the for 600kV is order on currently cables for development of MI cables MI of development Ref CIGRÉ 2013 April the in reported questionnaire The Table E22 years’ few next the ‘in 800kV of level voltage 10 to 15 years DC voltage of 750kV would be available within a for cables MI that indicated respondent one 1,800A of excess in capability a current-carrying achieve will Link HVDC Western the of cables Table in E22 illustrated is capability of MI according cables to current-carrying capability of the cable current-carrying the to match able be will which converters, CSC with used be may cables MI timescales for development and testing likely of ajudgement with together cables, PPL MI and MI of development the for forecasts of . 11 11 It has been assumed that, with some some with that, assumed been has It . 3 takes into consideration the range range the consideration into 3 takes 533 also addressed the forecast forecast the addressed also .533 Another expected to achieve a a to achieve expected .Another . 11
. . 10 The highest DC voltage MI cables at 500kV are are 500kV at cables .MI . The expected availability . 9 In his response, . This is consistent 533 survey .533 . 4 The .The
.
.
. 68 9
Appendix E 69 A A G G G G G G G G G G 2035 2035 2035 A R G G G G G G G G G G 2030 2030 2030 A A R G G G G G G G G G 2025 2025 2025 R R R G G G G G G G G G 2024 2024 2024 A R R R G G G G G G G G 2023 2023 2023 A R R R G G G G G G G G 2022 2022 2022 A R R R G G G G G G G G 2021 2021 2021 A A A R R R G G G G G G 2020 2020 2020 A A A R R R R G G G G G 2019 2019 2019 A A A A R R R R G G G G 2018 2018 2018 A A A A R R R R G G G G Technology potentially in service subject to contract to service subject in potentially Technology service in be to scheduled service or in Technology Technology potentially in service subject to contract to service subject in potentially Technology service in be to scheduled service or in Technology Technology potentially in service subject to contract to service subject in potentially Technology service in be to scheduled service or in Technology Technology not available not Technology service in not but available Technology Technology not available not Technology service in not but available Technology 2017 2017 2017 Technology not available not Technology service in not but available Technology A A A A R R R R R R G G 2016 2016 2016 Key Key Key 700kV 525kV 700kV 320kV 650kV 650kV 500kV 400kV 600kV 600kV 1876 A 2000 A 2000 Table E22.4 Table Mass impregnated cables at 55˚C and MIPPL cables at 80˚C – Current Table E22.3 Table Mass impregnated DC cables at 55˚C and MIPPL cables at 80˚C – Voltage Table E22.2 Table Extruded DC cable at 70 to 90˚C Electricity Statement Year Ten 2015 Appendix E number of examples exist a ±320kV, which is for present at service in The highest DC voltage for offshore converters equipment DC and valves the of insulation for required air in clearances platform physical dimensions due to the in particular, is subject to the limitations of constructed and installed be can that platforms the of weight and size offshore converters is dependent on the The achievable transmission capacity of under construction HVDC converters is illustrated in Table in E22 illustrated is converters HVDC The forecast availability of offshore platforms for HVDC platforms Offshore 2015 Ten Year Statement Electricity Footnotes: see pages 78–79 pages see Footnotes: converters HVDC for platforms Offshore Table E22.5 600kV 500kV 650kV 700kV Key 2016 for offshore strategic optioneering strategic for offshore E22 –Technology Appendix availability G R R A 2017 Technology available but not in service Technology not available Technology in or service scheduled to be in service Technology potentially in subject service to contract . 15,16,17,18 G G R A 2018 . Based on installation 12,13,14 . The DC voltage, G G R A and more are are more and 2019 G G R A 2020 G G R A . 5 .
2021 G G G R deliverable to be thought is converter offshore a ±400kV size, yard fabrication and capability lifting vessel an increase in DC voltage to around ±500kV to around voltage DC in increase an or upgraded installation vessel would allow significantly (topsides lift capacity 48,000t). capacity lift (topsides significantly increase the largest available lifting capacity 2015, in will operations offshore to commence The lifting vessel AllseasPioneering Spirit, due of the vessel the of capacity full the to exploit required be would size yard fabrication in increase However, an a solution carried out to establish the feasibility of such lifts more or two in installation for design converter amodular by adopting achieved be also could Further design work would need to be to be need would work design .Further 2022 G G G R . A new .Anew 2023 In principle, higher DC voltages voltages DC higher principle, .In G G G R
2024 G G G R 2025 G G G A 2030 G G G G 2035 19 G G G G
.
70 Appendix E
. 71 7 .
. . From this Consequently, Consequently, . . . . The Skagerrak 4 8 . . A solution with a power transfer The expected developments in developments expected The .
. , commissioned combines in 2015, VSC However, beyond 2017 the DC current beyond . However, 2017 1 Further increases will be possible, possible, be will increases Further 11 . largely enabled by increases in cable DC cable in increases enabled by largely voltage capability of the VSC is expected have to converged with that of the cables point on, the power transfer capability of HVDC systems using line commutated converters will no longer be greater than that achievable with applications cable for VSCs The availability of HVDC systems where VSC converters located onshore are used with mass E22 Table in illustrated cables is impregnated The greater DC voltage permitted mass by extruded with compared cables impregnated cables allows greater ratings MVA be to achieved in a given year project although Skagerrak 4 is a monopole, the the monopole, a is 4 Skagerrak although be to 1400MVA allow would technology ±500kV at operating bipole a with achieved theHowever, DC current of around is 1400A within present limits and, in principle, 1563MVA or more could be achieved with existing technology indicate voltage cable and current converter that a 2000MVA solution might be in service by 2019 line where systems of availability The onshore located converters commutated are used with mass impregnated cables is E22 Table in illustrated converters with MI cables achieve to a power transfer capability of 700MW with a single DC 500kV at operating pole In contrast systems to using voltage-sourced converters, the DC current will not be limited theby capability of the converter but that by of the cables capability of 2250MW will be in service in on commissioning2017 of the Western HVDC Link
. . 6 . . If a . The Table Table 2 . .
. The forecast forecast The 3 . . For linecommutated The combination of DC of combination The . Many combinations of component component of combinations Many . 6 indicates that a 2000MVA solution would . Caithness Moray project will achieve a power transfer capability of 1200MW increases in the DC current and voltage levels of the converters and cables allow a continuing rating MVA achievable the in increase E22 might and 2017 by available commercially be potentially be in service 2021 by Footnotes: see pages 78–79 The availability of a given rating MVA ina given year is determined whichever by of lowest the has technologies component the availability DC current and DC voltage are possible; results are shown in the figures where an increase in DC current, DC voltage or both allows a higher ratingMVA for the system be to achieved given rating MVA is available in a given year, it follows that any lower value rating of MVA available be also will converters with systems HVDC onshore located The availability of HVDC systems where VSC with used are onshore located converters extruded cables is illustrated E22 in Table and France between interconnector The Spain, commissioning will achieve in 2015, a power transfer capability of 1000MW The forecast capability of systems comprising HVDC converters and DC cables is determined component the of capability forecast the by technologies illustrated in the previous figures. The achievable rating MVA in a given year is determined the by DC current and DC voltage technologies component the by permitted current and DC voltage permitting the increase permitting the voltage DC and current ratingin MVA is indicated in the figures. The maximum real power transmissible by the system may be less than the rating, MVA to converters for requirements on depending provide reactive power is plant compensation reactive converters, always provided as partof the scheme E22.2 – Technology availability (systems) availability E22.2 – Technology Electricity Statement Year Ten 2015 Appendix E HVDC systems comprising line commutated converters and mass impregnated cables impregnated mass and converters commutated line comprising systems HVDC Table E22.8 cables impregnated mass and VSCs comprising systems HVDC Table E22.7 cables extruded and VSCs comprising systems HVDC Table E22.6 2015 Ten Year Statement Electricity 3000MVA 3000MVA 2600MVA 2800MVA 2800MVA 2800MVA 2600MVA 2600MVA 2250MVA 2250MVA 2400MVA 1000MVA 1200MVA 2100MVA 1400MVA 1970MVA Key Key Key for offshore strategic optioneering strategic for offshore E22 –Technology Appendix availability 2016 2016 2016 G G R R R R R R R R R R A A A A 2017 2017 2017 Technology available but not in service Technology not available Technology available but not in service Technology not available Technology available but not in service Technology not available Technology in or service scheduled to be in service Technology potentially in subject service to contract Technology in or service scheduled to be in service Technology potentially in subject service to contract Technology in or service scheduled to be in service Technology potentially in subject service to contract G G G R R R R R R R A A A A A A 2018 2018 2018 G G G R R R R R R R A A A A A A 2019 2019 2019 G G G G R R R R R R R A A A A A 2020 2020 2020 G G G G G R R R R R R A A A A G 2021 2021 2021 G G G G G G R R R R A A A G G G 2022 2022 2022 G G G G G G R R R R A A A G G G 2023 2023 2023 G G G G G G R R R R A A A G G G 2024 2024 2024 G G G G G G G R R R R A A G G G 2025 2025 2025 G G G G G G G G G G G G R A A A 2030 2030 2030 G G G G G G G G G G G G R A A A 2035 2035 2035 G G G G G G G G G G G G A A A A 700kV 2000A 320kV 1875A 320kV 320kV 1563A 600kV 1875A 500kV 1400A 750kV 2000A 750kV 2000A 650kV 2000A 700kV 2000A 650kV 2000A 700kV 2000A 650kV 2000A 600kV 1875A 600kV 2000A 525kV 2000A 1875A 525kV 72 Appendix E 73
500kV 1875A 2000A 500kV 2000A 600kV 500kV 1875A 2000A 500kV 2000A 600kV 320kV 1400A 9 with Table 10 with10 . . G G G G G G G 2035 2035 G G G G G G G 2030 2030 . The availability of HVDC G G G G G G G . 2025 2025 Using mass impregnated cables impregnated mass Using . G G G G G G G 7 shows that the offshore platform . 2024 2024 . A G G G G G G 6 shows that offshore platform size does . .10 2023 2023 in such applications offers little or no increase increase no or little offers applications such in in rating beyond what can be achieved with cables extruded E22 not impose a significant restriction on the capability of HVDC systems with extruded cables over the range of voltage considered 600kV(up to DC) E22Table such voltage DC on restriction a imposes that the capability of MI cables cannot be fully exploited The comparison E22 of Table systems comprising VSC converters and mass or converter one where cables impregnated more is located offshore is shown inTable E22 The comparison E22 of Table A A G G G G G 2022 2022
. A A G G G G G 2021 2021 . So A A A A A A G 2020 2020 .
. A A A A A R G 2019 2019 A A A A A R G 2018 2018 . 9 A A A A R R G . Technology potentially in service subject to contract to service subject in potentially Technology service in be to scheduled service or in Technology Technology potentially in service subject to contract to service subject in potentially Technology service in be to scheduled service or in Technology Technology not available not Technology service in not but available Technology Technology not available not Technology service in not but available Technology 2017 2017 A A R R R R G 2016 2016 However, the However, DC current of the link, 14 Key Key 900MVA 1875MVA 1875MVA 2400MVA 2400MVA 2000MVA 2000MVA at around is well 1250A, within present limits In principle, anoffshore converter with a rating of 1000MVA or more could be achieved with be to needs allowance but technology, existing made for the project delivery time Table E22.10 Table HVDC systems comprising VSCs and mass impregnated cables (offshore) Table E22.9 Table HVDC systems comprising VSCs and extruded cables (offshore) Footnotes: see pages 78–79 HVDC systems with converters with systems HVDC located offshorelocated offshore, located are converters HVDC Where the size of the available platform may impose a limit on the DC voltage of the system the achievable rating MVA in a given year is determined the by lower of the DC voltages permitted the by cable and platform The availability of HVDC systems comprising where cables extruded and converters VSC one converter or more is located offshore is shown E22 in Table station, converter offshore Alpha DolWin The installed achieved in 2013, a DC voltage of ±320kV . Electricity Statement Year Ten 2015 Appendix E original supplier terminalsfurther without being restricted to the of connection by the future the in extended be may system HVDC aVSC that means This achievement of multi-vendor interoperability the is systems HVDC VSC for technology control and protection in development A further supplier by asingle offered the converter stations at each terminal was 2014 incommissioned Zhoushan in China in June was system HVDC VSC five-terminal first The suppliers protection and control three involved technical responsibility for the project, which Institute, China Southern Power Grid) had 2013 [22] atcommissioned Nan’ao in China in December was system HVDC VSC three-terminal first The have recently been commissioned systems HVDC VSC multi-terminal first world’s HVDC schemes are less well established VSC multi-terminal for control and Protection 1997 since service in established and the technology has been well are control and –protection generation –schemes including connections to wind For two-terminal, ‘point-to-point’ VSC HVDC with multi-vendor interoperability) terminal systems and multi-terminal systems complexity (two-terminal systems, multi- increasing of systems HVDC VSC control expected availability of protection and Table E22.11. the shows figure The in illustrated is systems HVDC VSC for The availability of control and protection HVDC protection and control 2015 Ten Year Statement Electricity Footnotes: see pages 78–79 pages see Footnotes: . 23 The control and protection system for for system protection and control The SEPRI (Electric Power Research Research Power (Electric .SEPRI for offshore strategic optioneering strategic for offshore E22 –Technology Appendix availability .
. 20,21 .
. .
. The The
.
. the onshore transmission system of offshore wind generation while reinforcing to 6000MW up of connection the facilitate will be assessed and the risks evaluated risks the and assessed be to need will scheme each for requirements The needed is guidance further and above the of by any covered not are that issues control and to which it is connected may raise protection systems or AC system the with link HVDC any It should be emphasised that the interaction of present at placed been to have known are 2018, contracts no but interoperability solution to be in by service service into put been recently has and available applications, the technology is commercially systems HVDC VSC terminal technology, there is experience service for two- control and to protection comes it when So years few next the within developed be and it seems likely that standard solutions will systems HVDC multi-terminal for protection and control of issues the addressing are CENELEC systems HVDC VSC multi-terminal of protection and control the for exist currently standards No New Jersey to Virginia from coast east the spanning network HVDC VSC multi-terminal offshore an to form stages complex more is US the in Connection Wind Atlantic The form a multi-terminal link by the connection of additional terminals to has been designed to permit future extension 2012 January in Link West South Sweden’s of phase first the forming connection HVDC aVSC for awarded was A contract It would be possible for a multi-vendor amulti-vendor for possible be would .It . The project is planned to be built in in built to be planned is project .The Working Bodies within CIGRÉ and . . 25 When completed, it . 24 For multi-terminal multi-terminal .For The scheme scheme .The .
. . .
74
Appendix E 2035
. 75
G G G G G G 2030
G G G G G G 2025 G G G G G G
.
320kV 2000A 320kV 2000A 550kV 2024 12, it has been12, . G G G G G G
G G 2023 2035
G G G G G G
. 2022 respondent one where , 9 G G
G G G G G G
2030 2021
G G G G G G
G G 2020 2025
G G G G G G 2019 G G A A G G G G 2024
. 533 in April 2013 2018 A A G G G G G G
The above is consistent with the results of a questionnaire sent prospective to HVDC CIGRÉ in published and manufacturers breaker Ref estimated that a rated voltage in excess of 550kV would be achievable and that such a device might be in service 2021 by indicated that HVDC breakers operating at >500kV with a breaking capacity of 16kA would be available within five years. Another indicated that a >500kV device would be years 10 within available would facilitate depends on the current limiting current the depends on facilitate would reactor that is used with the HVDC breaker, which may itself be subject limitation to in size For the purposes E22 of Table
2023 2017 A A G G G G Technology potentially in service subject to contract to service subject in potentially Technology service in be to scheduled service or in Technology Technology not available not Technology service in not but available Technology
G G 2016 2022 A A G G G G 27,28 G G .
Allowing . 2021 Key 26 12 . A G 2020 A A 2019 A A Control (two-terminal)Control . Other HVDC circuit breaker Control (multi-terminal) Control 2018 Technology not available not Technology service in not but available Technology Technology potentially in service subject to contract to service subject in potentially Technology service in be to scheduled service or in Technology Protection (two-terminal) Protection Protection (multi-terminal) Protection Protection (multi-terminal) Protection A A 2017 The increase in rated voltage that this 26 . A R Key Control (multi-terminal, multi vendor) multi (multi-terminal, Control 2016 for project timescales, the device might be in service 2020 by prototypes have been demonstrated Table E22.12 Table HVDC breaker circuit Table E22.11 Table HVDC protection and control Footnotes: see pages 78–79 The manufacturer of the first-mentioned HVDC circuit breaker envisages that the next will devices semiconductor of generation allow an increase in the breaking current to 16kA HVDC circuit breaker circuit HVDC circuit- HVDC the of availability expected The breaker is illustrated E22 in Table A hybrid HVDC circuit breaker designed for a rated voltage a rated of 320kV, current of 2kA and a current-breaking capability of 9kA has been verified in the laboratory. Electricity Statement Year Ten 2015 Appendix E believed to be possible are 1000mm² than more of sizes Conductor means that a single installation run is required Consolidating three cores into a single cable to land) (compared water in temperatures ambient lower generally by the extent some to helped is this but disadvantages, thermal some have does formation trefoil The (SWA) conventional (lower cost) steel wire armouring in the armour, allowing the use of more currents circulating reduces turn in This fields. magnetic cancel largely formation trefoil in fields because the three differently phased magnetic armour the in losses of problems to the Three-core cable designs offer a good solution submarine technology AC of development rapid in resulted has The global proliferation of offshore wind farms AC cables 2015 Ten Year Statement Electricity Footnotes: see pages 78–79 pages see Footnotes: years few last the for market cable submarine AC the of bulk the formed have types cable crossExtruded linked polyethylene (XLPE) range of power and voltage applications awide at (3c) sheaths lead individual oil and paper and (1c) fluid-filled using decades, for service in been have solutions (3c) three-core 420kV cable rated at 500MW on order on 500MW at rated cable 420kV over 100km has been achieved at a voltage of of avoltage at achieved been has 100km over cables is shown in Table in E22 shown is cables AC submarine three-core of availability The cost-effective more prove may solutions single-core distances, shorter for so cables, individual three of costs the than greater However, the material costs are generally been built at voltages up to 245kV up voltages at built been have 100kg/m nearly of weights and diameter to 230mm up of cores three with cables Single .
for offshore strategic optioneering strategic for offshore E22 –Technology Appendix availability . Single-core (1c) and . 32 A cable length of just just of length Acable . 13 . 30 , with a a , with . 31 . .
. . . 29
cables is shown in Table in E22 shown is cables The availability of single-core AC submarine possible are transfers power large very so to 3000mm²), up (theoretically cables 3c than sizes conductor larger much to use free are designs single-core needed be probably will runs equivalent land cables and three installation to the compared high be can costs material the same cross section as the conductors, so losses) armour armours to reduce circulating currents and bonding on land, (which involves conductive cross- by using resolved normally is problem this – fields magnetic by unbalanced affected temperatures) land and sea between differential the as well (as cores between spacing increased and configurations flat with associated characteristics thermal improved the from benefit solutions Single-core technology matures the as benefits bring could properties thermal better with materials “filler” Lighter challenging. prove could 100kg/m beyond weights because role a play also will difficulties handling sizes conductor sheaths and armouring required for increasing over common sized larger the manufacture to lines extrusion factory of capability the by limited to be likely is technology The solutions are also possible 275kV and 245kV and industry offshore the within standardisation voltage no is there yet as 200kV of avoltage by using achieved delivery and transmission distance can be 20km than more much to not reducing cables voltage higher and 400kV of range economic the with effects disadvantage higher voltage cables . 132kV A good compromise between power power between compromise .Agood 33 Unfortunately the increasing capacitive . 34 These can often be of almost almost of be often can .These Onshore and offshore offshore and .Onshore . However, they are are .However, they . . However, the .However, the 14 . However, .However, 76 Appendix E 77 G G G G G G 2035 2035
G G G G G G Overall, Overall, . 2030 2030 . G G G G G G 2025 2025 . Anticipated Anticipated . G G G G G G 2024 2024 G G G G G G 2023 2023 A A G G G G 2022 2022 HVDC systems between interoperability of achievement The equipment HVDC different suppliers’ circuit-breaker HVDC the of Introduction GIS DC of Introduction An increase in DC current of VSC HVDC semiconductor power higher as converters available become devices A continuing increase in the DC voltage of extruded and mass impregnated DC cables offshore of technology the in Developments platforms for HVDC converters allowing capabilities transfer power higher VSC multi-terminal of application The n n n developments include: developments n n n n guidance provide to intend These forecasts the within available be will technology what of individual projects of timescale possible, on known developments known on possible, capability transfer power in trends growing and the functionality of VSC HVDC links are likely play to an increasingly important role transmission British the as years future in volumes increasing accommodates system generation renewable of A A G G G G 2021 2021 A A G G G G 2020 2020 A A A A G G 2019 2019 . Following A A A R G G . In principle, it would would it principle, In 2018 2018 35 . A A A R G G Technology potentially in service subject to contract to service subject in potentially Technology service in be to scheduled service or in Technology Technology not available not Technology service in not but available Technology available not Technology service in not but available Technology Technology potentially in service subject to contract to service subject in potentially Technology service in be to scheduled service or in Technology 2017 2017 A A A R G G 2016 2016 . It has been widely used in AC Key Key 700MW 500MW 600MW 1200MW 1300MW 1000MW Table E22.14 Table cables submarine AC Single-core Table E22.13 Table Three-core submarine AC cables be possible develop to DC GIS for higher the base to which on little is there but voltages, development for timescales substations Offshore AC platforms for Offshore substations AC are significantly smaller in size and weight than those required for HVDC converter stations and the required power transfer capacity can usually be achieved without great difficulty. Conclusions Forecasts of the likely availability of key technologies for strategic wider works are based on state-of-the art and, wherever HVDC gas-insulated switchgear (GIS) switchgear gas-insulated HVDC Gas-insulated switchgear (GIS)is a compact air-insulated conventional to alternative switchgear systems for a number of years in applications substations as such limited, is space where in urban areas, but it has not yet been widely applied HVDC to systems developments in insulating materials, however, a 320kV GIS for HVDC applications has recently been introduced Electricity Statement Year Ten 2015 Appendix E (3) (3) (2) (1) 2015 Ten Year Statement Electricity (4) (14) (15) (13) (12) (11) (10) (9) (8) (7) (6) (5) (17) (16) (19) (18) (21) (20) (24) (23) (22) Available: http://www ABB, ABB sets world record in HVDC Light voltage level (online) level voltage Light HVDC in record world sets ABB ABB, Available: https://www Sinclair Knight Merz (SKM), Review of Worldwide Voltage Source Converter (VSC) High Voltage Direct Current (HVDC) (HVDC) Current Direct Voltage High (VSC) Technology Converter Installations Source (online) Voltage Worldwide of Review (SKM), Merz Knight Sinclair voltage-direct-current-hvdc-technology-installations Available: http://www (online) operation into 2015) 19 Spain August and France (Accessed between link HVDC of stations converter puts Siemens Siemens, ABB, ABB wins $800 million order for Scotland’s Caithness-Moray subsea power link (online) link power Available: subsea http://www Caithness-Moray Scotland’s for order million $800 wins ABB ABB, Gustafsson, A, et al, The new 525kV extruded HVDC cable system, Technical Paper, ABB Grid Systems, August 2014 August Systems, Grid ABB Paper, Technical system, cable HVDC extruded 525kV new The al, et A, Gustafsson, Prysmian Group, Successful commissioning of SylWin1 HVDC grid connection (online) CIGRÉ WG B4 WG CIGRÉ Available: http://www Frontier with the Central Plains (online) Main Grid 750kV HVDC Transmission Line Start Construction to Build the Silk Road of Electricity Connecting the Western State Grid Corporation of China, Southern Hami-Zhengzhou ±800kV UHVDC Transmission Project Second Xinjiang-Northwest NEMO LINK, NEMO LINK announces €500m contracts to build the first interconnector between GB and Belgium (online). (online). Belgium and GB 2015)between 19 August (Accessed: interconnector first the tobuild contracts €500m announces LINK NEMO LINK, NEMO Available: http://www Available: http://investoren.prysmian.com/phoenix.zhtml?c=211070&p=RssLanding_pf&cat=news&id=1661739 (online) million €800 worth 2015) 27 August awarded, ever (Accessed: project cable value highest the secures Prysmian Group, Prysmian Available: http://new (online) grid 2015) August 20 transmission (Accessed german the into energy clean of (MW) megawatts 800 integrates DolWin1 ABB, Available: http://www 2015 (online) April Status: Platform HVDC SylWin1 Sheet Fact Siemens, Siemens, Siemens receives major order for BorWin3 North Sea grid connection from TenneT (online) from 2015) August 20 connection grid (Accessed Sea North BorWin3 for order major receives Siemens Siemens, Available: http://siemens htm&content()=ET&content()=EM transmission Networks for Offshore Wind Farms, Stockholm, March 29-30, 2001 29-30, March Stockholm, Farms, Wind on Offshore for Workshop Networks International transmission Second farms, wind of connection for L-E, Light P, HVDC Juhlin, and Holmberg, AK, Skytt, pr2015060251emen toTenneT (online) HelWin2 Available: http://www connection grid Sea North fourth over hands Siemens Siemens, Alstom, Alstom HVDC Technology to Power America’s First Offshore Energy Link (online) Link Available: Energy http://www.alstom.com/press-centre/2013/1/alstom-hvdc-technology-to-power-americas-first-offshore-energy-link/ Offshore First America’s toPower Technology HVDC Alstom Alstom, ABB, ABB positions world’s most powerful offshore converter platform in the North Sea (online) Sea North the in platform converter offshore powerful most world’s positions ABB ABB, Available: http://new Alstom, Start of construction for DolWin gamma offshore converter platform (online) Allseas, Pioneering Spirit (online) Available: http://www Rendina, R, et al, The realisation and commissioning of the ±500kV 1000MW HVDC link Sardinia Island – Italian Peninsular Peninsular –Italian Island Sardinia link B1-101, HVDC Paper 2012 1000MW (SAPEI), CIGRÉ ±500kV the of commissioning and realisation The al, et R, Rendina, Available: http://www (online) HVDC with 2015) Sweden August 20 southern and (Accessed: central between supply power the Balancing Link West South Alstom, pdf?epslanguage=en-GB and DC Power Transmission, Birmingham, UK, 10-12 February 2015 10-12 UK, February AC on Birmingham, Conference Transmission, 11th Power DC and system, International VSC-HVDC multi-terminal Nan’ao the of P, Delivery Bordignan, and G, Bathurst, NR Electric, Zhoushan multi-terminal VSC HVDC project was put into service (online) Available: service into put http://www was project HVDC VSC multi-terminal Zhoushan Electric, NR Asplund, G, Eriksson, K, and Svensson, K, DC transmission based on VSCs, CIGRÉ SC 14 Colloquium in South Africa 1997 Africa South in 14 SC Colloquium CIGRÉ VSCs, on based transmission DC K, Svensson, and K, Eriksson, G, Asplund, for offshore strategic optioneering strategic for offshore E22 –Technology Appendix availability . 52, HVDC grid feasibility study, CIGRÉ Ref CIGRÉ study, feasibility grid 52, HVDC ...... abb abb abb siemens abb sgcc nemo-link htm&content()=EM htm&content()=EM ...... ofgem siemens siemens allseas alstom nrelect . . . . . com/press/en/pressrelease/?press=/en/pressrelease/2014/energy/power-transmission/et201404036 com/cawp/seitp202/e0311ee675bb33b3c1257dcb00300a8c com/systems/hvdc/references/dolwin1 com/systems/hvdc/references/dolwin2 com/cawp/seitp202/d975999eef89be7bc1257d49005d1863 . com .
. . .
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. . gov .
. com/Global/OneAlstomPlus/Grid/PDF/Supergrid/SouthWest%20Link%20HVDC%20project com/uk/19/equipment/pieter-schelte com/news-content-253 com/press/en/events/2015/energymanagement/2015-04-Inelfe . . . . (Accessed: 27 August 2015) . com/press/pool/de/feature/2013/energy/2013-08-x-win/factsheet-sylwin1-e com/press/en/pressrelease/?press=/en/pressrelease/2015/energymanagement/ cn/ywlm/mediacenter/corporatenews/05/272889 com/latest-news/ . . (Accessed 20 August 2015) uk/publications-and-updates/skm-review-worldwide-voltage-source-converter-vsc-high- . . (Accessed: 19 August 2015) . html . 533, April 2013 April 533, .
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. com/home . (Accessed August 28 2015) . ca/wind-power/wolfe-island-wind-project-1978-mw-wolfe-island . pdf on . . com/press/en/pressrelease/?press=/en/pressrelease/2014/energy/power-transmission/ . cn/PageFiles/391359/Nexans%20-%20Olivier%20Angoulevant uk/cawp/seitp202/d3cdc8eaf205a03cc1257acc002b5c90 uk/cawp/seitp202/cde9d973660941c3c12579a3002ab31e . . com/public/2fb0094306e48975c125777c00334767/XLPE%20Submarine%20Cable%20 . .
. co co . . com/docs/default-source/default-document-library/hybrid-hvdc-breaker---an-innovation- . abb . e . siemens abb powerauthority norway atlanticwindconnection abb ...... abb . (Accessed: 27 August 2015) August 27 (Accessed: . htm&content()=ET&content()=EM . Available: http://www Available: (Accessed 20 August 2015) ept201408064 Siemens, Siemens presents first gas insulated 320kV switchgear for direct current transmission,(online). Ontario Power Authority, Wolfe Island WindProject (197 Available: http://www Available: ABB, ABB million wins $170 contract for world’s longest high voltage subsea http://www cable AC Available: (online) Worzyk, Submarine T, Power Cables, Springer 2009 Nexans, At the core of performance, Offshore Wind China Bergen, 2010, March 15 (online) 2010 Available: http://www Available: Callavik, M, Blomberg, A, Häfner, J and Jacobson, B, The hybrid HVDC breaker: (online) grids HVDC An innovation breakthrough enabling reliable Available: http://new Available: breakthrough-for-reliable-hvdc-gridsnov2012finmc20121210_clean.pdf?sfvrsn+2 Davidson, Whitehouse, C C, R S, Barker, and C D, Dupraz, A new ultra-fast J-P, HVDC circuit-breaker International11th for Conference meshed DC networks, on and AC DC Power Transmission, Birmingham, February UK, 10-12 2015 Systems%202GM5007%20rev%205 Available: http://library Available: ABB, XLPE submarine cable systems, (online) Tahata, K, Kamei, K, Yoshida, Yamamoto, D Kono, R, and Y, Ito, H, HVDC circuit-breakers for HVDC International grid applications,11th Conference on and AC DC Power Transmission, Birmingham, February 10-12 2015 Available: http://www Available: Atlantic Wind Connection, Atlantic Wind Connection (online) Connection Wind Atlantic Connection, Wind Atlantic ABB, ABB wins $30 million order for world’s highest voltage three-core subsea AC cable (online) Available: http://www Available: (34) (35) (33) (32) (31) (31) (26) (27) (28) (29) (30) (25) (25) Electricity Statement Year Ten 2015 Appendix E AIS Switchgear Bay Switchgear AIS E23.4 Table Transformers E23.3 Table Current Sourced Converters E23.2 Table Converters Sourced Voltage E23.1 Table 2015 Ten Year Statement Electricity Onshore Equipment Costs 250MVA–132/33/33kV 250MVA–150/33/33kV 180MVA–132/33/33kV 300MVA–220/132kV 250MVA–220/33kV 3000MW–500kV 2000MW–500kV 2200MW–500kV 1000MW–400kV 1800MW–500kV 1000MW–320kV 1200MW–320kV 800MW–320kV Specifications Specifications Specification Specification Unit costs E23 – Appendix 350MVA 400kV 275kV 132kV Cost (£M) Cost (£M) Cost (£M) Cost (£M) 210–226 133–148 160–175 170–185 125–142 100–115 114–130 117–132 3 3 3 2 . 3 3 . 0 1 . 1 ...... 1–3 8–3 . 8–4 . 5–4 3–4 7–4 . 1–1 . 1–1 . 7–1 . . . 4 4 0 8 2 4 0 0 2
HVAC GIS Switchgear Bay Switchgear HVAC GIS E23.7 Table Quadrature Booster E23.6 Table Shunt CapacitorShunt Banks E23.9 Table Shunt Reactors E23.8 Table Series Compensation E23.5 Table 2750MVA–400kV 200MVAr–400kV 100MVAr–220kV 400MVA–400kV 400MVA–400kV Specifications Specifications Specifications Specifications Specifications 60MVAr–33kV 200MVAr 100MVAr 400kV 220kV 150kV 275kV 33kV Cost (£M) Cost (£M) Cost (£M) Cost (£M) Cost (£M) 1 . 8 .5–10 0 . 3 . 4 . 3 2 . 2 . 7 3 5 1 . . 35–1 . . . . 9 – 8 0–5 4–3 . 3–0 . 0–2 . 3–3 9–4 . 0–1 7–4 –7 8 ...... 7 65 2 2 5 4 . 5 0 3 8 5 3 80 Appendix E 81 8 . 24 .44 . 2–17 . .4–26 86–6 . 15 4 Cost (£M) Cost 22 50MVAr 100MVAr 200MVAr Specifications Table E23.11 STATCOMs .1 7 . .1–16 5 –11 . 9 13 Cost (£M) Cost 100MVAr 200MVAr Specifications Table E23.10 Compensators VAR Static Electricity Statement Year Ten 2015 Appendix E HVAC GIS Switchgears Switchgears HVAC GIS E23.15 Table Transformers E23.14 Table Current Sourced Converters E23.13 Table Converters Sourced Voltage E23.12 Table 2015 Ten Year Statement Electricity Offshore EquipmentOffshore Costs 250MVA–132/33/33kV 250MVA–150/33/33kV 180MVA–132/33/33kV 300MVA–220/132kV 250MVA–220/33kV 3000MW–500kV 2000MW–500kV 2200MW–500kV 1000MW–400kV 1800MW–500kV 1000MW–320kV 1200MW–320kV 800MW–320kV Specifications Specifications Specifications Specification Unit costs E23 – Appendix 350MVA 400kV 220kV 150kV 275kV 33kV Cost (£M) Cost (£M) Cost (£M) Cost (£M) 0 . 175–185 217–228 157–166 1 –125 110 3 3 3 . 3 . 3 3 2 . 3 0 2 84–94 . 14–0 ...... 0–3 . 9–4 . 9–4 . 3–3 . 5–4 . 5–4 . 3–2 7–3 N/A N/A N/A 4 – 6 . 9–1 . .1 0 2 5 0 0 8 2 2 3 2
Static VAR Compensators E23.18 Table CapacitorShunt Banks E23.17 Table Shunt Reactors E23.16 Table STATCOMs E23.19 Table 200MVAr–400kV 100MVAr–220kV Specifications Specifications Specifications Specifications 60MVAr–33kV 200MVAr 200MVAr 200MVAr 100MVAr 100MVAr 100MVAr 50MVAr Cost (£M) Cost (£M) Cost (£M) Cost (£M) 28 .5–29 19 12 17 4 . 6 . 9 . 6 . 3 1 ...... 0–4 . 4–6 . 3–9 . 3–6 . 0–1 0–19 –17 0 4–12 4 – 8 .1 3 7 3 5 6 . . . . 3 6 3 0 82 Appendix E 83 512 820 442 402 325 580 325 589 530 704 850 551 .490 .490 N/A N/A 220kV 220kV 379–0 . 407–0 . 537–0 .656 270–0 . 270–0 . 520–0 . 492–0 .665 464–0 .628 520–0 .640 360–0 . 330–0 . 444–0 . 435–0 . 700–0 . 480–0 . .400–0 .400–0 0 . 0 . 0 . 0 . 0 . 0 . 0 . 0 . (£M per km) 0 . 0 . 0 . 0 . 0 . 0 .680–0 . 0 . 0 0 0 . 320kV–400kV (£M per km) 500kV–550kV (£M per km) 370 878 447 457 482 444 522 522 522 780 260 755 706 530 562 N/A N/A N/A 150kV 415–0 . 522–0 . 213–0 . 475–0 . 478–0 .648 330–0 . 426–0 . 426–0 . 426–0 . 384–0 . 300–0 . 395–0 . 365–0 . 560–0 .685 0 .616–0 . 0 . 0 . 0 . 0 . 0 . 0 . 0 . 0 . 0 .650–0 . (£M per km) 0 .649–0 . 0 . 0 . 0 . 0 . 0 . 0 . 220kV–320kV (£M per km) 400kV–500kV (£M per km) Rating Rating 150MW 250MW 350MW 200MW 400MW 300MW 800MW 800MW 600MW 1200MW 1200MW 1500MW 1500MW 1800MW 1800MW 1000MW 1000MW 2500MW 2000MW 2000MW Rating per Rating single cable single per pair of cables per pair of cables Onshore Cable – Supply Table E23.22 Table 3 CoreHVAC Cables (copper conductor) Table E23.21 HVDC Extruded Cables (copper conductor) Table E23.20 HVDC Mass Impregnated Cables (copper conductor) Electricity Statement Year Ten 2015 Appendix E HVAC 3 × Single Core Cables (aluminium conductor) (aluminium Cables Core HVAC 3×Single E23.25 Table conductor) (aluminium Cables Extruded HVDC Table E23.24 conductor) (copper Cables Core HVAC 3×Single Table E23.23 2015 Ten Year Statement Electricity per pair of cables of pair per single cable single cable Rating per Rating per 1000 MW 1000 MW 1200 MW 1200 Unit costs E23 – Appendix 1000MW 900 MW 900 600 MW 600 600 MW 600 800 MW 800 800 MW 800 500 MW 500 700 MW 700 900MW 800MW 600MW 500MW 700MW Rating Rating 220kV–320kV (£M per km) per (£M 220kV–320kV 0 . (£M per km) per (£M km) per (£M 0 . 0 . 0 . 0 . 0 0 0 . 0 . 0 0 0 ...... 398–0 .670 548–0 .618 506–0 . 313–0 . 718–0 . 576–0 . 834–1 . 834–1 . 418–0 964–1 2 –1 925 –1 925
220kV 220kV N/A N/A N/A N/A .128 .128 .178 008 008 877 382 704 510 486 320kV–400kV (£M per km) per (£M 320kV–400kV 0 . . 0 .653–0 . 0 .653–0 . 0 .600–0 0 . (£M per km) per (£M km) per (£M 0 . 0 . 0 . 0 . 0 . 0 . 0 0 0 . 0 . 0 . . . . 720–0 . 290–0 . 366–0 . 437–0 . 469–0 . 469–0 . 410–0 . 313–0 896–1 896–1 . 673 551–0 . 673 551–0 . 418–0 400kV 400kV 400kV . . 095 095 534 502 382 880 800 800 510 733 356 447 574 574 84 Appendix E 85 95 95 95 95 95 95 N/A N/A N/A N/A N/A 4–0 .65 4–0 .65 4–0 .65 4–0 .65 4–0 .65 4–0 .65 4–0 .65 4–0 .65 58–0 . 58–0 . 58–0 . 58–0 . 58–0 . 58–0 . 400kV 0 . 0 . 0 . 0 . 0 . 0 . 0 . 0 . 0 . 0 . 0 . 0 . 0 . 0 . (£M per km) 320kV–400kV (£M per km) 500kV–550kV (£M per km) 95 95 95 95 95 .17 N/A N/A N/A N/A N/A 4–0 .65 4–0 .65 4–0 .65 4–0 .65 4–0 .65 4–0 .65 4–0 .65 4–0 .65 77–1 58–0 . 58–0 . 58–0 . 58–0 . 58–0 . . 220kV 220kV 0 . 0 . 0 . 0 . 0 . 0 . 0 . 0 . 0 0 . 0 . 0 . 0 . 0 . (£M per km) 220kV–320kV (£M per km) 400kV–500kV (£M per km) Rating Rating 700MW 500MW 800MW 800MW 600MW 800MW 600MW 900MW 1200MW 1200MW 1500MW 1500MW 1800MW 1800MW 1000MW 1000MW 1000MW 2500MW 2000MW Rating per Rating single cable single per pair of cables per pair of cables Table E23.28 3 × SingleHVAC Core Cables Table E23.27 HVDC Extruded Cables Table E23.26 HVDC Mass Impregnated Cables Onshore Cable – Installation – Cable Onshore Electricity Statement Year Ten 2015 Appendix E Electricity Ten Year Statement 2015 Ten Year Statement Electricity Overhead lines Overhead E23.29 Table MVA Rating/Circuit 3000MW 4000MW 2000MW 1000MW Unit costs E23 – Appendix (£M/ route) (£M/ 1 . 132kV 132kV N/A N/A N/A . 5–1 8
275kV (£M/ route) (£M/ 275kV 1 . 1 . N/A N/A . 0–1 . 5–1 7 4 400kV (£M/ route) (£M/ 400kV 2 . 1 . 1 . 1 . . 0–2 . 0–1 . 5–1 . 5–1 9 9 5 6 86 Appendix E 87 875 512 550 550 589 530 482 390 390 551 704 784 032 N/A N/A 220kV 220kV 379–0 . 407–0 . 898–1 . 537–0 .657 522–0 . 394–0 . 492–0 .665 464–0 .628 800–0 . 320–0 . 320–0 . 340–0 . 433–0 . 435–0 . 460–0 .640 400–0 . . 0 . 0 .641–0 . 0 . 0 0 . 0 . 0 . 0 . (£M per km) 0 .632–0 .690 0 . 0 . 0 . 0 . 0 . 0 . 0 . 0 . 0 . 320kV–400kV (£M per km) 500kV–550kV (£M per km) 311 878 447 875 440 482 530 499 560 720 706 562 N/A N/A N/A N/A 150kV 254–0 . 415–0 . 522–0 . 826–0 . 478–0 .648 330–0 . 508–0 .620 508–0 .620 508–0 .620 482–0 . 395–0 . 384–0 . 360–0 . 433–0 . 0 . 0 .610–0 . 0 . 0 . 0 . 0 . 0 . (£M per km) 0 .649–0 . 0 . 0 . 0 . 0 . 0 . 0 . 0 . 0 . 220kV–320kV (£M per km) 400kV–500kV (£M per km) Rating Rating 150MW 250MW 350MW 200MW 400MW 300MW 800MW 800MW 600MW 1200MW 1200MW 1500MW 1500MW 1800MW 1800MW 1000MW 1000MW 2500MW 2000MW 2000MW Rating per Rating single cable single per pair of cables per pair of cables Table E23.32 3 CoreHVAC Cables (copper conductor) Table E23.31 HVDC Extruded Cables (copper conductor) Table E23.30 HVDC Mass Impregnated Cables (copper conductor) Offshore Cable – Supply Electricity Statement Year Ten 2015 Appendix E HVAC 3 Core Cables (aluminium conductor) (aluminium Cables HVAC 3Core E23.35 Table conductor) (aluminium Cables Extruded HVDC E23.34 Table conductor) (copper Cables Core HVAC 3×Single E23.33 Table 2015 Ten Year Statement Electricity per pair of cables of pair per single cable single cable Rating per Rating per 1000 MW 1500 MW 1500 1200 MW 1200 Unit costs E23 – Appendix 1000MW 600 MW 600 800 MW 800 300 MW 400 MW 400 200 MW 200 350 MW 350 250 MW 250 150 MW 150 900MW 600MW 800MW 500MW 700MW Rating Rating 220kV–320kV (£M per km) per (£M 220kV–320kV 0 . 0 . 0 . 0 . 0 . (£M per km) per (£M 0 . (£M per km) per (£M 0 . 0 . 0 . 0 1 . 1 . . 433–0 . 360–0 . 620 508–0 .620 508–0 .620 508–0 .686 562–0 . 594–0 . 423–0 . 254–0 1 . 1 . .
1 . 220kV 150kV 150kV . 95–1 . 07–1 . 07–1 . 15–1 . 18–1 N/A N/A . 2–1 43 43 7 26 530 726 440 517 311 6 6 320kV–400kV (£M per km) per (£M 320kV–400kV 0 . 0 . 0 . 0 . 0 . 0 . 0 . . 0 .646–0 (£M per km) per (£M (£M per km) per (£M 0 . . 0 .641–0 0 1 . . 490–0 . 460–0 . 433–0 . 320–0 . 320–0 . 394–0 .691 565–0 .657 537–0 0 0 0 1 . . 400kV 400kV 220kV . 18–1 . 96–1 . . . . 8–1 . 8–1 . 8–1 . 3–1 N/A 74 26 26 26 56 784 26 790 390 390 482 530 598 562 88 Appendix E 89 56 26 26 26 26 74 0–1 . 8–1 . 8–1 . 8–1 . . . . 94–1 . 04–1 . 400kV . 1 . 0 0 0 1 . 0 (£M per km) 26 43 43 6 0–1 . N/A N/A 95–1 . 95–1 . 85–1 . 220kV 220kV 1 . . . . 0 0 0 (£M per km) 700MW 500MW 800MW 600MW 900MW 1000MW Rating per Rating single cable single Table E23.36 3 × SingleHVAC Core Cables (aluminium conductor) Electricity Statement Year Ten 2015 Appendix E Table E23.38 E23.37 Table CableOffshore – Installation 2015 Ten Year Statement Electricity Grounding barge for shallow waters Dredging Pipeline/cable crossing HDD Vessel de/mobilisation Single cable, single trench, three core 2 single cables; 2 trenches, three core, 10M apart core, three 2trenches, cables; 2 single 2 single cables; 2 trenches, single core, 10M apart core, single 2trenches, cables; 2 single Twin cable, single trench, single core Single cable, single trench, single core Unit costs E23 – Appendix Installation Additional Costs Installation Installation TypeInstallation
1 . 1 . 0 3 £M/km 5–10 £M 5–10 0 0 £M/km 0 . 3 £M/km 3 £M/km 3 . 0 1 . 33–1 . . Cost 53–1 . .1–2 25 £M 25 . 3–0 . 5–1 . 3 2 .2 25 7 90 Appendix E 91 48 –74 36–50 30–40 585–715 340–410 510–630 640–785 810–990 660–795 720–880 730–895 390–495 805–990 440–500 400–490 560–680 485–600 Total Costs (£M) Costs Total Total Costs (£M) Costs Total Total Costs (£M) Costs Total Ratings Ratings Ratings . For full details on costs and assumptions used, please contact 1750MW/450–550kV 1750MW/450–550kV 2500MW/650–750kV 2500MW/650–750kV 1250MW/320–400kV 1250MW/320–400kV 2250MW/600–700kV 2250MW/600–700kV 1500MW/450–500kV 1500MW/450–500kV 1000MW/320–400kV 1000MW/320–400kV 2000MW/500–600kV 2000MW/500–600kV 200–400MW/33kV arrays/132–150kV 200–400MW/33kV arrays/220–275kV 400–600MW/66kV arrays/220–275kV 400–600MW/66kV The indicative technology or installation costs required to enable the economic analysis have required The indicative technology or installation costs . and anonymised and aggregated exercise suppliers via a procurement from been gathered overheads and basic assumptions as have been applied to these costs and the costs Standard in ranges to establish high level generic unit costs including installation, have been presented be should however, of such costs testing and commissioning . The generic and indicative nature and will be subject to market and actual costs on specific schemes may be different recognised conditions at the time of order Manjinder Dhesi on [email protected] Table E23.40 Self-installation Platform – DC Table E23.41 Platforms AC Table E23.39 DC Platforms – Jacket andTopside Platforms Electricity Statement Year Ten 2015