PJM Generator Interconnection Request Queue # H21_W68 Greenland Gap 300 MW Facilities Study Report
November 2004
1 Description of Project
NedPower Mt. Storm LLC (NedPower) has proposed a new 300 MW generating facility consisting of two hundred 1500 kW wind turbine generators for a summer maximum total output of 300 MW at their Greenland Gap site in Grant County, West Virginia. The project will be connected as an energy-only resource by looping the existing Mt. Storm – Meadowbrook 500kV circuit into the new Allegheny Power (AP) Greenland Gap 500kV switching station. The Nedpower project is planned as a multiple stage project with the first phase to be commercial in 2006 and an anticipated later phase completing the buildout. The wind turbine generators will extend across a larger project area generally following a North-to-South layout along the Allegheny Front. The existing Mt. Storm – Meadowbrook circuit generally runs with a West-to-East orientation crossing the Nedpower site. The Nedpower substation (collecting the wind turbine generated power at 35 kV and transforming to 500 kV) is assumed to be adjacent to the AP station. The proposed in-service date for this project (initial energization of the substation for backfeed to the wind farm) is August of 2006, with completion of the initial phase of the project being in commercial operation by October of 2006. (See Amendments to System Impact Study Data).
The intent of this study is to define the cost and construction schedule for the new AP switching station, for the necessary system reinforcements, and protection requirements to accommodate the above generation.
Amendments to System Impact Study Data or System Impact Study Results
The modifications to the data or results from the System Impact Study includes (1) changing the final configuration of the new Greenland Gap switching station, and (2) the revision of the in-service date. Based on an assumed execution date of the ISA/CSA of January 3, 2005, and a 20 month engineering/construction schedule, the expected in-service date is August of 2006 with a commercial date of October 2006.
Developer’s Milestone Schedule
The customer has submitted the following schedule for the construction of their facilities:
Execution of Interconnection Service Agreement January 3, 2005 Begin Engineering January 2005 Begin procurement of long-leadtime equipment February 2005 Start Site Prep; Excavation; Concrete July 2005 Complete 500 kV Interconnection Transmission Line May 2006 Receive Backfeed Power from 500 kV System June 2006 Initial Test Power to Grid July 2006 Complete Construction and Start-up of Turbines September 2006 Facility Commercial Operation October 2006
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Developer’s Scope of Work
The developer proposes to construct a new 300 MW generating facility consisting of two hundred 1500 kW wind turbine generators for a summer maximum total output of 300 MW at their Greenland Gap site in Grant County, West Virginia. The developer will connect the generation facility to the interconnection point via a rigid bus structure from the customer substation into the new AP Greenland Gap switchyard as shown in Attachment 1.
Description of Facilities Included in Study
This report describes the electrical interconnection facilities necessary at AP’s new Greenland Gap switching station necessary at the substation to support the developer’s generation. The Developer’s Transmission line construction and the Developer’s Generation facilities are not included in this study. There will also be relay changes required at Mt. Storm, to be done by Dominion, which are also not included in this study. These changes are addressed in the Generation Interconnection Facilities Study Report Supplement completed by Dominion – Electric Transmission and dated July 14, 2004.
AP Scope of Work for Facilities included in this Study
1. Transmission Lines – New
The existing Mt. Storm –Meadowbrook 500 kV circuit will be looped into the new Greenland Gap switching station via two spans of conductor (one in, one out). These transmission line segments will be constructed and owned by AP.
2. Transmission Lines – Upgrades
No transmission line upgrades are required to be constructed by AP.
3. New Substation / Switchyard Facilities
The new Greenland Gap 500 kV switching station with a three breaker ring bus configuration will be constructed by AP to accommodate the interconnection.
4. Upgrades to Substation / Switchyard Facilities
Purpose and Necessity
The developer will be interconnected to the AP system at the new 500kV Greenland Gap switching station as shown in Attachment 1.
3 Protective equipment at Dominion’s Mt. Storm substation and AP’s Meadowbrook substation will be upgraded to accommodate the new Greenland Gap switching station.
General Description of Functional Design and Layout
The new Greenland Gap 500 kV switching station will be constructed with a ring bus configuration.
Major interconnection equipment required for this installation will include two line dead end structures, one rigid bus connection to the customer substation, three 500 kV 3,000 ampere 50 kA circuit breakers, eight 500 kV 3,000 ampere air switches, three optical metering units, and miscellaneous additional protective relaying, metering and communications equipment as required to accommodate this interconnection.
During detailed design and analysis other components may be identified for this interconnection.
Permits Required
The Developer has notified AP that it has applied for and received a Certificate of Public Convenience and Necessity (CPCN) from the West Virginia Public Service Commission (WVPSC) for the Project. The new Greenland Gap switching station will be located on property controlled by the developer and immediately adjacent to the existing 500 kV transmission line. The construction of the switching station was addressed as part of the CPCN application and testimony. It is the understanding of the Developer that no additional CPCN permit is required for the switching station since it was included in the CPCN that was issued by WVPSC, and no further authorization, permit, or approval is required.
AP has also concluded that no additional CPCN permit will be required for the transmission line work. In the event that an additional CPCN permit is required, AP estimates that the CPCN Application Process (filing and certification) will take approximately 5 months, assuming no complications and no opposition to the Application. Any additional time required for this process will extend the project schedule. It is assumed that AP will require local building permits for the construction. Permits required by the developer are not addressed in this report.
5. Upgrades to Substation / Switchyard Facilities
Electrical Design
General Design Requirements The electrical design will be in accordance with the applicable laws and regulations of the federal government, the state of West Virginia, and the local codes and ordinances.
4 The 500kV general design requirements are as follows:
• System phasing (counter clockwise) 1-2-3 • System frequency: 60 hertz • Elevation, AMSL: 3100 feet • Isokeraunic level: 40 • Maximum ambient temperature: 40 degrees C • Minimum ambient temperature: -35 degrees C • Maximum bus and jumper conductor operating temperature 100 degrees C • Maximum wind velocity: 80 mph • Maximum ice loading: 1.25 inches • Seismic zone: 1
Voltage and Current Ratings
The voltage and current ratings are as follows:
• Nominal phase-to-phase: 500kV • Maximum phase-to-phase: 550kV • Basic impulse level (BIL): 1800kV • Maximum continuous current carrying capacity 3000A • Maximum three phase available fault current: 50kA • Maximum single phase to ground available fault current 50kA • Maximum fault clearing time 15 cycles
Clearances and Spacings
Substation Clearances and Spacings are as follows:
• Rigid bus center-to-center phase spacing 336 inches • Minimum phase-to-phase, metal-to-metal distance: 300 inches • Minimum phase-to-ground: 152 inches • Low bus height above top of foundations: 360 inches • High bus height above top of foundations: 660 inches • Minimum vertical clearance from live parts to grade: 246 inches • Minimum horizontal clearance from live parts: 180 inches • Minimum conductor clearance above roads in switchyard: 432 inches • Minimum bottom of insulator to top of foundation: 102 inches
Rigid Bus System
The rigid bus size is anticipated to be 5 inch schedule 80 and will be verified during the detailed design. The rigid bus will be designed based on continuous current, fiber stress and deflection criteria. The rigid bus will be designed for a maximum deflection of one pipe outer diameter with ice. Porcelain station post insulators will be used on all bus
5 supports and disconnect switches and the mechanical ratings will be determined during the detailed design.
Grounding System
The grounding system will be designed in a manner that provides a means to safely discharge lightning strokes to earth, reduce step and touch potentials to safe levels, and confine dangerous soil currents to inaccessible areas. The grounding system will also be designed to allow the detection of ground fault currents by protective relaying systems, limit electromagnetic interference {EMI) in low voltage circuits, and provide a common ground reference. The grounding procedures stated herein are based on ANSI/EEE Standard 80-1986.
Lightning Shielding System
The shielding design will be verified using the application of that model called the “Rolling Sphere Technique” developed by R. H. Lee.
After the detailed bus and equipment layout is completed, the shielding design will be analyzed to verify that all equipment within the switchyard perimeter fence is adequately protected. Structure lightning finials and shield wires will be included in the shielding analysis.
Raceway and Control Cable Systems
The main raceway systems will consist of pre-cast cable trench. Underground conduit will be PVC with PVC fittings buried not less than 24 inches below grade.
The control building cable raceways will utilize overhead cable tray, wireway, and conduit.
All single and multi-conductor power and control cables will be specified to AP standards. The conductors will be multi-conductor, jacketed cable. Cable for lighting and AC power will be shielded.
Control Buildings
A new station control building will be constructed in accordance the National Electric Safety Code.
AC Station Service System
The AC station service system located in the AP control building will be a 120/208V, three phase, four wire system with a minimum rated capacity of 250 kVA.
125V DC System
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The 125V DC system will be located in the AP control building will consist of a single battery set and charger. The charger and associated battery set will be capable of providing emergency operation and continuous load for the substation.
Structural Design
The steel structures will be designed using the Ultimate Strength Design (USD) method. Design and fabrication will be in accordance with AP design standards, and consistent with the latest edition of the AISC “Manual of Steel Construction,” ASCE 7-98, the NESC and the ASCE Publication 72. All structure stresses will remain below ultimate (yield) stresses specified in the appropriate ASTM specification.
Material Specifications
Circuit Breaker Specifications
Circuit breakers will be provided in accordance with AP standards and the following requirements:
500kV Breaker Specifications: a) Type: Dead tank, group operated b) Rated maximum voltage: 550kV rms c) Rated voltage range factor, K: 1.0 d) Rated low frequency withstand voltage: 860kV rms e) Rated full wave impulse withstand voltage: 1800kV peak f) Rated chopped wave impulse withstand voltages: Two microseconds minimum time to sparkover: 2320kV peak Three microseconds minimum time to sparkover: 2070kV peak g) Rated capacitance switching current: Overhead line charging current: 500 A Definite purpose Shunt capacitor bank or cable: 500 A Definite purpose h) Rated shunt reactor switching current: N/A i) Full wave impulse withstand voltage for interrupters and resistors: 1800kV peak j) Rated transient recovery voltage, as rated exponential-cosine envelope: Rated peak voltage of 1 minus cosine curve, E2: 968kV Rated time to peak voltage of 1 minus cosine curve, T2: 1325microseconds k) Multiple exponential curve crest voltage, E1: 674kV l) Rated transient recovery voltage rate, R: 1.6kV/microsecond m) Rated delay time, T1: 2 microseconds
7 n) Rated continuous current: 3000 amperes rms (The generator circuit breakers rated continuous current may be sized for the respective turbine generators maximum continuous current output). o) Duty cycle: O+0s+CO+15s+CO p) Rated short-circuit current: 50,000 amperes rms q) Required capabilities: Minimum symmetrical interrupting capability: 50,000 amperes rms Short-time (3 second) current carrying capability: 50,000 amperes rms Closing and latching capability: 130,000 amperes peak r) Rated interrupting time: 2 cycles (60 hertz basis) s) Rated permissible tripping delay, Y: 1 second t) Rated reclosing time: 20 cycles (60 hertz basis) u) Adjustable reclosing range: 15-45 cycles (60 hertz basis) v) Tripping logic for low SF6 gas operating pressure: Trip and Block Close w) Bushing data: Type: Composite Basic impulse level: 1800 kV Minimum creepage distance: 318 inches Color: ANSI 70 gray x) Nominal station service power supply voltages: Auxiliary power: 120/208 three phase VAC Breaker closing: One coil rated at 125 volts dc Breaker tripping: Two coils rated at 125 volts dc y) Current transformer data:
Quantity, Accuracy Location Ratio Each Bushing Total Class 1X-3X-5X 3000/5 1 3 C800 1Y-3Y-5Y 3000/5 1 3 C800 2X-4X-6X 3000/5 1 3 C800 2Y-4Y-6Y 3000/5 1 3 C800
Outdoor Disconnect Switch Specifications
500kV Disconnect Switch Specifications: a) Type: Vertical break, group operated b) Operation: Motor c) Maximum voltage: 550kV rms d) Continuous current: 3000 amperes rms e) Impulse withstand voltage (BIL): 1800kV peak f) Short-time withstand (symmetrical) : 70,000 amperes g) Peak withstand current: 164,000 amperes h) Number of poles: 3 i) Switch phase spacing: 28 ft j) Motor operator shall be rated for operation at: 125 volts dc
8 k) Manual operator shall be: Worm gear type l) Motor operator auxiliary switch contacts in addition to those required for motor operator control: Minimum number “a” type: 8 Minimum number “b” type: 8
Coupling Capacitor Voltage Transformer or Voltage Transformer Specifications
500kV Coupling capacitor voltage transformers (CCVTs) or voltage transformers (VTs) will be provided in accordance with the following requirements: a) Nominal voltage: 500kV (line-to-line) b) Impulse withstand voltage (BIL): 1800kV peak c) Total CCTV minimum capacitance: 5000 pF or as required for circuit breaker TRV capacitance d) Ratio: 2500/4500:1 e) ANSI accuracy class: 0.3 W, X, Y, Z and ZZ
Metering Unit Specifications
500kV Optical Metering units will be provided in accordance with the following requirements: a) Nominal voltage: 500kV (line-to-line) b) Impulse withstand voltage (BIL): 1800kV peak c) Primary current rating: 2X Design Rating d) CT ratio: Sized during Design e) CT accuracy class: 0.3 f) CT thermal rating factor: 2.0 g) CT mechanical current rating: 108,000 A rms symmetrical h) CT short-time 3s thermal current rating: 40,000 A rms maximum i) VT ratio: 2500:1 f) VT accuracy class: 0.3 g) Porcelain minimum creepage distance: 440.2 in
Surge Arrester Specifications
500kV Surge arresters will be provided in accordance with AP standards and the following requirements: a) Type: MOV b) Nominal voltage: 500kV (line-to-line) c) Maximum operating system voltage: 550kV rms d) Arrester class: Station e) Duty cycle voltage : 396kV f) MCOV voltage: 318kV
9 g) Maximum switching surge protective level: 874kV peak @2kA for a surge rise time of 45 micro-seconds h) Maximum 0.5 microsecond discharge voltage: 1161kV peak for a 4x20 micro-second wave
Protective Relaying, Metering, Monitoring, and Communications
Transmission Line Relaying
Primary Relaying
Primary relaying will be a Directional Comparison Blocking scheme using power line carrier. The manufacturer, type and model number for the protective relay will be determined during the detailed design. Typical clearing time is anticipated to be in the 3 cycle range (1 cycle fault detection and 2 cycle breaker clearing time) for all faults.
Secondary Relaying
Secondary relaying will be a Step Distance scheme. The manufacturer, type and model number for the protective relay will be determined during the detailed design. Total clearing time is anticipated to be in the 3 cycle range (1 cycle fault detection and 2 cycle breaker clearing time) for zone 1 faults. Zone 2 backup clearing time is anticipated to be in the 22 cycle range (2 cycle fault detection, 18 cycle zone 2 timer, and 2 cycle breaker clearing time).
Breaker Reclosing
Automatic circuit breaker re-closing and sync check will be provided on all circuit breakers. Delayed reclosing are used for transmission line faults.
Breaker Failure (Stuck Breaker) Relaying
Breaker failure relaying will be provided for each circuit breaker. The manufacturer, type and model number for the protective relays will be determined during the detailed design. The breaker failure relay timer will be set for 7.5 cycles, for a total clearing time of 12.5 cycles for pilot and zone 1 faults (2 cycle fault detection, 7.5 cycle breaker failure timer setting, 3 cycle breaker clearing time). Breaker failure clearing time for non-pilot time delayed trips will be approximately 30 cycles.
The breaker failure relays for the generator circuits will sense both the over-current and position status (52a) of the protected circuit breaker. The overcurrent elements will be set at minimum pickup. The breaker failure relays for the transmission line circuits will sense only the over-current status of the protected circuit breaker.
10 Generator Circuit Relaying
The Generating Facility transmission line connected at the new Greenland Gap switching station will be designed with two sets of line current differential relays using fiber-optic communications that will provide protection for the line feeding from the generation station.
General Purpose Metering
Three-phase ampere metering will be provided for each circuit breaker. Three-phase Ampere, Watt, VAr and Voltage metering will be provided for each circuit.
Three-phase Ampere, Watt, VAr, and Voltage metering at the turbine generator terminals will be provided to AP via the SCADA RTU.
Revenue Metering
Optical Metering units will be provided to revenue meter each interconnection circuit at the point of common coupling (PCC). The manufacturer, type and model number for the revenue meters will be determined during the detailed design.
SCADA RTU
SCADA RTUs will be provided for AP and PJM monitoring. The manufacturer, type and model number for the SCADA RTUs will be determined during the detailed design.
Digital Fault Recorder
PJM requires a fault recorder for all generating stations greater than 500MW and/or major transmission substations. Interconnection Customer will coordinate with AP to determine the number of quantities that must be monitored, and the type of fault recording equipment needed to be compatible with existing AP fault recording systems.
Communications
AP will install telecommunication optical fiber circuits, EMS and relaying equipment interfaces, and make all associated upgrades to existing equipment.
Engineering Design Schedule
Following is the proposed schedule for the AP portion of the project. This timeline is based on receipt of an executed Construction Service Agreement and executed Interconnection Service Agreement by January 3, 2005. Any delays in executing these agreements will further delay the project timeline.
11 Activity Start Finish Project Management Receipt of Executed Construction Service & Interconnection 1/3/2005 Agreements Kick Off/Estimate/Schedule/Baseline 1/17/2005 1/31/2005 Engineering Line Line Design 500 kV 1/31/2005 7/25/2005 Procure Line Materials 500 kV 6/20/2005 12/12/2005 Issue Line Engineering 500 kV 7/25/2005 Substation Substation Design 500 kV 4/18/2005 6/27/2005 Order Substation Material 500 kV 5/2/2005 6/6/2005 Issue Substation Engineering 500 kV 6/27/2005 Controls Controls, SCADA & Metering Design 500 kV 5/2/2005 9/5/2005 Order Controls, SCADA & Metering Material 500 kV 6/6/2005 6/27/2005 Issue Controls, SCADA and Metering Engineering 9/5/2005 Construction Management Bid & Purchase Order Process 6/20/2005 9/19/2005 Obtain PSC Approvals/Permits 6/20/2005 12/12/2005 Construction * Substation 500kV equipment 9/12/2005 5/1/2006 Controls Controls, Cables, Panels, Racks, Etc. 4/10/2006 5/29/2006 Line 500kV Line 12/12/2005 6/12/2006 Test & Energize 500kV 5/22/2006 7/10/2006 In Service 7/10/2006 As-Built Revisions 7/3/2006 9/4/2006
* Includes two month weather-related work delay
Material Specifications Included above.
Material Lists
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A detailed material list will be provided by AP upon completion of detailed design. See Attachment 4 for a preliminary material list.
Summary of Results of Study
Assumptions:
The following assumptions were made to prepare this Facility Study:
1. A complete graded site with access to be provided by developer at no cost to AP. 2. All excess spoils/rock to be wasted on site and rehabilitated accordingly. 3. All coordination with controls and line work available without any demobilization required. 4. All controls testing and relay work to be performed by AP. 5. Control building pricing includes installation of water and HVAC. 6. Based on 10-month construction schedule. 7. From a protection standpoint, Greenland Gap features three breakers in a ring configuration (electrically). The design for the controls for Greenland Gap substation will rely heavily upon previous designs. This will substantially lower the controls engineering costs. 8. The protection for the 500kV line from the switching station to the generator site requires the installation of two fiber-optic communication cables. The equipment required at the generator site, which is not included in this estimate, will cost roughly $50,000. 9. Any relaying changes at Meadowbrook Substation will be minimal 10. The relays at Mt. Storm may need to be replaced. The precise cost and scope will need to be determined in conjunction with Virginia Power, as Mt. Storm is a Virginia Power station, and the 500kV Mt. Storm - Meadowbrook line, which is being cut to insert Greenland Gap, is jointly owned by Allegheny Power and Virginia Power. 11. Overall fenced area 700 ft x 550 ft. 12. Average ground grid conductor spacing of 20 ft 13. A-frame 500kV dead-end structures 14. Includes AP 500kV group operated switch at point of service 15. Foundations = 2,000 yds concrete (90% caisson or 1,800 yds & 10% pads or 200 yds) 16. 40% rock in caissons or 720 yds. An adder will have to be applied to estimate for caisson rock removed over 720 yds. The estimate for caisson rock removal is $300/yd. 17. 20% rock in pads or 40 yds. An adder will have to be applied to estimate for pad rock removed over 40 yds. The estimate for pad rock removal is $100/yd. 18. No rock excavation is required in top two feet of substation yard normal excavation required for ground grid and control cable installation. 19. No Screening requirements 20. The line will require two tap structures (3 individual steel poles for each structure) and span directly into the new switching station. 21. The in-line tap structures will be guyed with pad & pier foundations. 22. The line will be approximately 500' per circuit.
13 23. Need to reconductor one of the shield wires to Mt. Storm as an OPT-GW (3.15miles). 24. No r/w clearing necessary 25. No access road construction necessary 26. No major grading/site work to access and work steel pole structures and anchors 27. One (1) mobilization and demobilization 28. R.O.W. for the 500kV lines into the substation will be provided at no cost to AP. 29. The CPCN Application Process (filing and certification), if required, will take approximately 5 months, assuming no complications with and no opposition to the Application. Any additional time required for this process will extend the project schedule. 30. There are no environmental issues associated with station or line work. 31. Outages can be obtained when requested. 32. All construction is done as per the Allegheny Power Construction Standards Manual. 33. All construction is done as per PJM Philosophy and Design Standards.
AP High Level Milestone Schedule
Begin Engineering January 2005 Begin Procurement Activities May 2005 Begin Construction September 2005 Test and Energize May 2006 Available to Energize Customer Equipment July 2006 Initial Test Power to Grid from Wind Farm August 2006 Facility Commercial Operation October 2006
This schedule will slide based on any delays in the process.
Direct Attachment Facilities
Station Controls and Associated Equipment $662,000 Breakers $1,330,000 Switches $330,000 Meters $162,000 Other Equipment $4,810,000
Line Conductors $99,000 Shield Wires $71,000 Poles $265,000 Other Equipment $127,000
Site Development $127,000
Engineering, Support, and Other Expenses $519,000
14 Overheads $749,000
Contingencies $461,000
Total Direct Attachment Facilities $9,712,000
Network Upgrade Facilities
None
Total Project Cost $9,712,000
The AP schedule is based on a ten month construction schedule, with two months of winter weather delay added. Uncertainties on the AP end include the weather, availability of outages to perform the work in the substation, and equipment delivery. With proper lead time for PJM outage notification and ordering of equipment, two of the three issues should not be a problem.
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Information Required for Interconnection Service Agreement
The following table contains the cost breakdown as required by FERC.
Attachment Facilities Network Facilities
Direct Charges Labor $4,357,000 $0
Direct Charges Material $4,496,000 $0
Indirect Charges Labor $859,000 $0
Indirect Charges Material $0 $0
Carrying Charges $0 $0
Schedule of Payments
January 2005 $49,400 February 2005 $16,500 March 2005 $16,500 April 2005 $1,984,350 May 2005 $969,350 June 2005 $969,350 July 2005 $969,350 August 2005 $574,350 September 2005 $574,350 October 2005 $613,500 November 2005 $613,500 December 2005 $613,500 January 2006 $613,500 February 2006 $613,500 March 2006 $521,000
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ATTACHMENTS
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List of Attachments
Attachment 1 : High Level Planning Diagram Depicting Interconnection Facilities and Points of Ownership/Demarcation
Attachment 2: Single Line Diagram
Attachment 3: Greenland Gap Station Bus and Equipment Arrangement Diagram
Attachment 4: Detailed Material List
18 Attachment 1
19
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Attachment 4 DETAILED MATERIAL LIST - Greenland Gap Station Construction Facility Study Report Queue # H21_W68 - Greenland Gap 300MW
Category Quantity Detailed Description Unit High Level Description
Controls 3 EHV BREAKER CONTROL PANEL EA Panels 3 EHV LINE PROTECTION RELAY PANEL EA Panels 2 EHV TRANSFER TRIP RACK EA Panels 1 ALARM CABINET EA Panels 3 TRANSFER TRIP EQUIPMENT EA Panels Material 1 ANNUNCIATOR PLC MATERIAL EA Panels Material 2 EHV LNE PILOT RELAY (PRIMARY) EA Panels Material 2 FIBEROPTIC LINE RELAY W/TRANSFER TRIP EA Panels Material 2 EHV LINE NON-PILOT RELAY (BACKUP) EA Panels Material 1 1 LOT FIBEROPTIC TERMINATION EQUIPMENT EA Panels Material 1 DIGITAL FAULT RECORDER EA Panels Material 1 SYNCHRONISM SCOPE PANEL EA Panels Material 1 ALARM LO Panels Material 3 LINE PROTECTION PANEL LO Panels Material 3 EHV BREAKER PANEL EA Panels Material 9 500KV CVT WITH CARRIER EA CVTS 2 4000 A TRAP, WB EA TRAP 2 WB TUNER EA TUNER 2 TRANSMITTER RFL 9785P EA TRANSMITTER 8 AIR SWITCH MOTOR MECH FOR 500 KV SWITCHES EA MOAS 1 RTU, QEI, 6CPP6, STD, 16A, 32S, 16C, 1P EA SCADA RTU 500 STATION SERVICE CABLE FT CABLE 1,200 EHV GAS BREAKERS FT Cable 1,200 EHV 3 PHASE CVTS FT Cable 2,400 EHV DISCONNECTS HR Cable 1 PHONE LINE INSTALLATION (INCLUDES LABOR) LOT TELEPHONE CIRCUIT 1 POSITRON AND LINE SHARING SWITCH EA TELEPHONE CIRCUIT 1 COMM FIBER EQUIPMENT FOR NUG EA MISC. SCADA EQUIPMENT 1 SUBSTATION COMPUTER & EQUIPMENT EA MISC. SCADA EQUIPMENT 1 DIGITAL FAULT RECORDER EA MISC. SCADA EQUIPMENT 1 RFL LOOPBACK REMOTE UNIT EA MISC. SCADA EQUIPMENT 1 STATES SLIDE-LINK TERMINAL BLOCK EA MISC. SCADA EQUIPMENT 1 LOOPBACK POWER SUPPLY EA MISC. SCADA EQUIPMENT 1 SEL 2030 RELAY CONCENTRATOR EA MISC. SCADA EQUIPMENT Meters 1 FREE STANDING METER RACK EA Meter Racks 2 ION METERS EA METER EQUIPMENT 1 MISC. METERING ITEMS LOT METER EQUIPMENT 1 OPTICAL METER UNIT EA Miscellaneous Equipment Substation Equipment 720 ROCK (CAISSON - 1800 YD) 40% ROCK YD GENERAL 40 ROCK (PAD - 200 YD) 20 % ROCK YD GENERAL 38,850 GROUND GRID, 4/0 COPPER WIRE FT General 2,400 ROADWAY - 14 FT INSIDE FENCE FT GENERAL 2,500 RENCE FT GENERAL 9,240 YARD STONE (tons) [0.024Tons/Sq.Ft. for a 6" layer] TON General 1,000 CABLE TROUGH 20 IN WIDE FT GENERAL 300,000 STEEL - FROM P.O. OR BLANKET (#) LB GENERAL 2,000 CONCRETE (cu. yds.) including DEADEND FOUNDATIONS YD General (90% CAISSON, 10% PADS) 1 CONTROL BULDING - 32' X 52' (ERECTED) EA GENERAL 1 CONTROL BULDING - 16' X 24' (ERECTED) FOR GENERATOR EA GENERAL 1 AC DISTRIBUTION CUBICLE-INDOOR EA GENERAL 2 STATION SERVICE FEEDERS EA GENERAL 1 MAINTENANCE BUILDING 32' X 52' (ERECTED) EA GENERAL 1 CONTROL BUILDING - INSIDE MATERAL TOTAL GENERAL 1 TELEPHONE PROTECTION EQUIPMENT LOT GENERAL 1 CABLES, 600V, UG, FOR GENERATOR EA GENERAL 1 COMMUNICATIONS CIRCUIT - 1 MILE, INSTALLED EA GENERAL 4,500 CABLE FOR YARD LIGHTS AND REC EA GENERAL 1 BATTERY 450AH, 125V, WITH RACK EA GENERAL 1 BATTERY CHARGER, 75 AMPS, 125V DC EA GENERAL 1 EMERGENCY GENERATOR 250 KW WITH TRANSFER SWITCH EA GENERAL 1 FUEL TANK, UG, FOR GENERATOR EA GENERAL 1 MISC. STOCK MATERIAL TOTAL GENERAL 3 BREAKER, 500 KV, 3000 A, 50 KA EA 500 KV 3 CURRENT TRANSFORMER, 500 KV, 1 PHASE EA 500 KV SWITCH, DISCONNECT, WITH MOTOR MECHANISM, 3 PHASE, 8 500KV, 3000A, WITHOUT INSULATOR EA 500 KV 6 INSULATOR ASSEMBLIES, DEADEND, 500KV EA 500 KV 1 TRANSFORMER, STATION SERVICE EA 500 KV 6 CAPACITOR VOLTAGE TRANSFORMER(CVT), 500 KV EA 500 KV 210 INSULATORS, STATION POST 50 KV EA 500 KV 9 ARRESTORS, SURGE 396 KV EA 500 KV 100 TUBING, BUS, 5 NCH AL., 39 FOOT LENGTH EA 500 KV 1 MISC. STOCK MATERIAL - 500 KV TOTAL 500 KV Site Development 1 CORE BORING LS 6 CONSTRUCTION TRAILER MTH 1 GATES EA 50 CONCRETE TESTING - CYLINDER BREAKS EA Lines 0.15 DOUBLE CIRCUIT CONDUCTOR WIRE 2032.1 (BUNDLED) MI 2.50 SINGLE CIRCUIT SHIELD WIRE (OPT-GW) MI
1 0.15 DOUBLE CIRCUIT SHIELD WIRE 7#6 MI 2,500 ANCHOR GUYS FOR TAP POLES (26 GUY WIRES TO FT 12 FOUNDATIONS 100,000 STEEL FOR POLES LB 130 CONCRETE FRO FOUNDATIONS ( PAD & PIER PLUS YD ANCHOR GUYS )
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GENERATION INTERCONNECTION FACILITIES STUDY REPORT SUPPLEMENT
2006 SUMMER – 300 MW WINTER – 300 MW
PREPARED FOR:
PJM Interconnection, LLC Queue # H21_W68 Greenland Gap Wind Farm Project
Date July 14, 2004
Prepared By: Dominion - Electric Transmission
Generation Interconnection Study: 2006 Summer WIND FARM 1 Table of Contents
Description Page
Introduction 3
Power Flow Analysis 4
Stability Analysis 8
Short Circuit Analysis 9
Construction Requirements 10
Conclusions and Recommendations 11
Appendices 12
Generation Interconnection Study: 2006 Summer WIND FARM 2
Introduction
PJM contacted Dominion regarding a generation interconnection request they had received in their queue (Queue # H21_W68) for 300/300 megawatts (summer/winter) of wind turbine generating capacity at the Customer’s proposed site approximately 3 miles east of Mount Storm Power Station. This proposed facility is located on the border of Dominion and PJM West, in the vicinity of several critical tie lines. Consequently, Dominion determined that generation interconnection studies were needed to evaluate the impact of this request on Dominion’s transmission facilities.
This study assumed the new plant output would be connected to the 500 kV Mount Storm-Meadowbrook transmission line.
Since this site is not located in Dominion’s service area, and there is no request for transmission service, this new generation was modeled as not serving Dominion load. Nothing in this study should be interpreted to imply that off-system sales capability from this site currently exists, or will exist at any time in the future without a formal request for transmission service, and subsequent additional studies to determine whether transmission system improvements may be required.
A Facilities Study is defined as a technical analysis conducted by the Transmission Provider to determine the required modifications to the Transmission Provider’s Transmission System. This includes the cost and scheduled completion date for such modifications as required to interconnect the proposed generation. The costs for modifying the Transmission system are separated and categorized as Direct Assigned Facilities and Network Upgrades. Direct Assigned Facilities are those transmission facilities necessary to make the interconnection to the transmission system for the specific benefit of the Customer. Network Upgrade Facilities are those transmission facilities that require upgrading due to overloading or network system protection due to the new interconnection.
For study purposes, the following generating capacity was used at the proposed wind turbine generator site:
Study Year Summer/Winter Capacity Summer (MW) 2006 300/300
Generation Interconnection Study: 2006 Summer WIND FARM 3 Power Flow Analysis
Study Methodology and Procedure
Each power flow analysis performed by Dominion is accomplished through the use of the PSS/E Power Flow software developed by Power Technologies, Incorporated (PTI). An extensive database, encompassing neighboring utilities, is used to analyze the interconnected transmission system under anticipated operating conditions that include provisions for single contingency outages, and variations in power import and export levels. Specific to generation interconnection analysis, the following criteria are taken into consideration:
• Transmission facility loading • First Contingency Incremental Transfer Capability (FCITC) • Normal Incremental Transfer Capability (NITC) • System Protection • System Stability
Base Case Development:
The summer peak season is the most limiting, operationally, on the Dominion bulk power transmission system. Therefore, the summer season was evaluated in detail so as to represent a worst case condition. Once the summer season has been evaluated, additional analysis, based on winter peak condition, is performed, as needed.
Summer and winter base cases were developed from the 2002 Series of VST base cases for use in this generation interconnection study to evaluate the interconnection of 300 MW at this site.
Study Case Development (General) and Subsequent Activities:
Dominion develops an AC power flow case for each study alternative it is tasked to investigate. Upon completion of a power flow case, MUST software developed by Power Technologies, Incorporated (PTI) is used to yield an estimate of the effects of pre- specified outages that comprise single contingencies. The results for the reference base case are compared to the proposed generation base case and any additional overloaded transmission components identified in the generation base case (loaded to 94% or greater) would need to be relieved through proposed network upgrades or new installations. Upon identification of the most critical contingencies, AC power flows are run to more precisely analyze the outage scenarios.
The following cases were developed for this study:
Generation Interconnection Study: 2006 Summer WIND FARM 4 S06A – 2006 Summer base case from the 2002 Series of VST base cases with the following higher queued generators modeled: GI-1A at 465 MW, GI-1B at 465 MW, GI-12 at 900 MW, GI-19 at 550 MW, GI-86 at 550 MW, GI-99 at 912MW, GI-102 at 750 MW, GI-137 at 41 MW, and GI-138 at 76 MW.
S06B – Case S06A with 300 MW modeled at the proposed site.
W09A – 2009/10 Winter base case from the 2002 Series of VST base cases with the following higher queued generators modeled: GI-1A at 555 MW, GI-1B at 555 MW, GI-12 at 900 MW, GI-19 at 550 MW, GI-86 at 550 MW, GI-99 at 949 MW, GI-102 at 750 MW, GI-137 at 141 MW, and GI-138 at 52 MW.
W09B – Case W09B with 300 MW modeled at the proposed site.
Power Flow Study Results
Contingency Analysis
Dominion uses a 94% facility loading value as a trigger point for relieving specific transmission facilities through upgrades or new installations. To accommodate higher queued generation and the proposed 300 MW wind farm, generation was dispatched off- line in northern and eastern Virginia and at Bath County. As with any power flow study, a different generation dispatch will yield different results.
Overloaded Elements with Number of Contingencies and % Overload Based On 100% Rating
Overloaded Elements Base Case WIND FARM (S06A) (S06B) None
Overloaded Elements with Number of Contingencies and % Overload Based On 94% Rating
Overloaded Elements Base Case WIND FARM (S06A) (S06B) None
The above Tables indicate that no Dominion facilities require upgrades in order to interconnect 300 MW of wind powered generation to the transmission system. The winter study results are consistent with summer results.
Generation Interconnection Study: 2006 Summer WIND FARM 5 Transfer Study Results
An area to area transfer of 2000 MW to and from American Electric Power (AEP), Allegheny Power (AP), Carolina Power & Light (CPLE), and Pennsylvania-New Jersey- Maryland power pool (PJM) was performed on the study base cases to determine if any facilities limit transfers without the proposed generation. Then, an area to area transfer of 2000 MW was performed on the interconnection study case with the proposed generation modeled to check for any limits to transfers caused by the new generation. For transfer studies, Dominion uses a 100% facility loading value as a trigger point for relieving specific transmission facilities through upgrades or new installations.
In order to conduct an evaluation of transfer capability in the study cases described in the above section, Power Technology, Incorporated’s MUST software program was used. In the study, a facility was not considered a valid limit if the facility’s response to transfers was below 3 percent (per industry standards). It is possible, therefore, for a facility to be overloaded in the contingency analysis but not be shown as a limit to transfers because of the low response factor. Transfer capabilities were determined simulating transfers from one area to another independently, i.e. AEP to DOMINION, and non-simultaneously with other area transfers. All transfers were tested at the 2000 MW test level. The 2000 MW transfer study level comes from Dominion’s Planning Guidelines, which state that the transmission system should be capable of supplying peak loads without exceeding any facility’s thermal rating for the loss of the two largest generators at one generating station. For Dominion’s system, this would be the loss of the two North Anna units.
The following tables contain the results of the transfer analysis:
Exports
Base WIND Limiting Facility Outage Facility Case FARM (S06A) (S06B)
AEP 2000+ 2000+ No Limit Found
AP 2000+ 2000+ No Limit Found
CPLE 2000+ 2000+ No Limit Found
PJM 2000+ 2000+ No Limit Found
Generation Interconnection Study: 2006 Summer WIND FARM 6
Imports
Base WIND Limiting Facility Outage Facility Case FARM (S06A) (S06B)
AEP 2000+ 2000+ No Limit Found
AP 2000+ 2000+ No Limit Found
CPLE 2000+ 2000+ No Limit Found
PJM 2000+ 2000+ No Limit Found
The transfer study results indicate that Dominion exports and imports are greater than 2000 MW, and not adversely affected by the proposed generation.
Generation Interconnection Study: 2006 Summer WIND FARM 7
Stability Analysis
Study Methodology and Procedure
A transient stability study was performed for the Greenland Gap Wind Turbines using PJM supplied dynamic model/data. The breaker arrangement on the 500 kV side (Mt. Storm-Meadowbrook line) is assumed to be a three-breaker ring. This arrangement will trip the entire wind generator plant for any 500 kV breaker failure at the site. There will be approximately 200 wind turbines (1.5 MW each, 0.575 kV), having 300 MW total plant capacity. Each wind turbine will be connected to the 500 kV transmission system via an individual 0.575-34.5 kV GSU transformer. For one-line and study purposes, these individual GSUs are represented by an aggregated, 175 MVA transformer equivalent. To step the voltage to 500 kV, two 34.5-500 kV, 200 MVA each transformers are also represented.
The one-line diagram in Appendix A reflects the data represented in the stability case as received from PJM (June 8, 2004 case for the projected 2007 system conditions). The scheduled in-service date for this project is December 2006. The PJM case data indicates that half the units will be connected to one 34.5 kV bus and the other half to another 34.5 kV bus and each set will have a 34.5-500 kV transformer. The total output from all units will be connected at 500 kV at the plant and only one feed will be going to the 500 kV three-breaker ring switching station.
This study was performed to evaluate the impact of this additional 300 MW generation on Dominion system stability. The stability study results indicate no adverse impacts on Dominion's system at this time. It should be noted that the model/data used in this study is generic and any major changes in the model and/or data may alter the study results. Also, the Customer is responsible for protecting its equipment from disturbances on Dominion system.
Generation Interconnection Study: 2006 Summer WIND FARM 8 Short Circuit Analysis
Study Methodology and Procedure
A general System Protection review was completed to determine the impact to the Dominion system as a result of the proposed wind powered generation. Typically the biggest impact from a protection standpoint is the additional short circuit currents supplied to the system and the affect it has on the interrupting capabilities of the circuit breakers.
Each case is studied through the use of Advanced System Power Engineering's Oneliner (ASPEN) short circuit software. A separate breaker ratings module is used to perform the breaker ratings check. The short circuit model includes the entire Dominion transmission and generation system along with the impact of the surrounding interconnecting utilities and any planned new generation on the system. A 95% breaker duty value is used as a trigger point to upgrade these facilities.
System Protection Study Results:
There is no impact to breaker interrupting capabilities as a result of the Greenland Gap Wind Farm project. These results are based on estimated data and are subject to change with system conditions.
Generation Interconnection Study: 2006 Summer WIND FARM 9 Construction Requirements
The proposed 300 MW Greenland Gap Wind Farm generating facility, located in Grant County, West Virginia, will be connected to the 500 kV Mount Storm-Meadowbrook transmission line. The following is a summary of the work required to connect and unload this generation into the Dominion transmission system.
500KV SUBSTATION WORK - MT. STORM:
The age of the existing Line 572 relays at Mt. Storm Substation, plus the short distance between Mt. Storm Substation and the Greenland Gap generating site, may result in the line relays proposed at the wind farm site being incompatible with the existing Line 572 relays. This would have adverse impacts on reliability.
To insure proper coordination between these line relays, Dominion must replace the existing Line 572 relay panel at Mt. Storm Substation. At the appropriate point in the project schedule, Dominion and APS protection engineers will need to get together to coordinate the line relay requirements and construction schedules.
The estimated cost to upgrade the Line 572 relay panel is $80,000.00.
Summary of Interconnection Costs - Greenland Gap Wind Farm
Interconnection Construction Requirements – Direct Assigned
Direct Assigned Facilities: Transmission (None): $ 0.00 Substation (None): $ 0.00 Total: $ 0.00
There are no Direct Assigned Facilities on Dominion's transmission system associated with the Greenland Gap Wind Farm.
Interconnection Construction Requirements – Network Upgrades
See detailed construction requirements above.
Network Upgrade Facilities: Transmission (None): $ 0.00 Substation (R/P Line 572 Relay Panel): $ 80,000.00 Total: $ 80,000.00
Generation Interconnection Study: 2006 Summer WIND FARM 10 Conclusions and Recommendations
In summary, Dominion performed load flow, short circuit and stability studies for the proposed Greenland Gap Wind Farm generation at an output of 300 MW, consistent with information and data provided by PJM as of June 11, 2004.
With the exception of replacing the Line 572 line relay panel at an approximate cost of $80,000.00, as outlined above under Construction Requirements, no problems or issues were identified that adversely impact Dominion's transmission system at this time.
Generation Interconnection Study: 2006 Summer WIND FARM 11 Appendix A
Greenland Gap Wind Farm One – Line Diagram (Reflects data represented in the stability case received from PJM on June 11, 2004)
To 500kV interconnecting substation designed by PJM/Allegheny Power/Dominion (three - breaker ring)
Generation Interconnection Study: 2006 Summer WIND FARM 12