Index

acid rain 206 bias voltage 122, 123 active (real) power 116, 269 bid-price auction 223 active governor 62 bilateral contracts 222 active networks 245 bilateral trading 221 active stall control 33 biodiesel 243 aggregation 34 bioethanol 243 aggregation effects 57, 58, 73; for wind 30 8, 9, 14, 15 air density 31 2, 9, 11, 12, 15, 16, 50 air gap 99 anaerobic digestion 51 alternating current (AC) 112, 255, 256 combustion 51 alternator 98 gasifi cation 51 annual charge rate 197 pyrolysis 51 anthropogenic warming 5 BJT 123 apparent power 268 236 asynchronous generator 98, 112 blackout 56, 67 asynchronous link 142 blade feathering 32 automatic voltage regulator (AVR) 160, block tripping 190 161, 162 boiler 17 auto-reclose circuit breakers 189 boost converter 134 auxiliaries (in power stations) 56, 64 boundary layer 27, 28 availability of power 58, 70, 71 bridge circuit 124, 125 automatic voltage controller (AVC) 161 British Electricity Transmission and average penetration 19 Trading Arrangements (BETTA) 223 buck converter 134 back-up 70, 71, 78 building integrated wind turbines 238, 239, balancing impact 72 240 balancing market COPYRIGHTED226, 227 bus MATERIAL164 balancing reserve 70 22, 23, 64, 71 cadmium telluride PV cells 241 base load plant 201 cage 112, 113 batteries 57, 92 capacitance 259 Betz limit 32 capacity credit 71, 72, 74, 75, 204, 213

Renewable Energy in Power Systems Leon Freris and David Infi eld © 2008 John Wiley & Sons, Ltd 278 Index (for wind turbine) 32 credible contingency 64 (for solar thermal plant) 42 crowbar 191 capacity factor 71, 74, 196 crystalline PV 37 capital costs 195, 196, 197 current source inverter 128 carbon capture and storage (CCS) 8, 9, 13 curtailment 76, 79, 80 carbon cycle 3 cut-in wind speed 31 carbon dioxide 3 cut-out wind speed 31 atmospheric levels 4 carbon sinks 207 DC supergrid 237 carbon taxes 208, 216 DC-DC converters 133 carbon trading 4, 208, 210 deferrable loads 58, 93 Carnot limit 11, 12 delta connection 275 cascade tripping 67 demand curve 56 cash-fl ow analysis 210 demand matching 57, 64 cellulosic crops 51 demand-side management 58 Central Electricity Generating Board depreciation 197, 211, 212 (CEGB) 213, 218 deregulation 71, 205, 221 centralized generation 152, 175 diode 122 Chernobyl 205 diode rectifi er 124, 125 chopper 133 direct current (DC) 127 circuit breakers 17, 169, 171 direct drive (gearless) wind turbine 146 clean development mechanism (CDM) 207 discarded energy 76, 79, 80 climate change 4, 5, 7, 8 discount rate 197 mitigation 6, 7, 8, 11 dispatching (generation) 21, 22, 32, 33 models 6 dispersed sources 57, 72, 73, 78, 82 Climate Change Levy 217 distortion 185 1, 2, 3, 4, 9, 10, 11, 12 19, 175 gasifi cation 13, 22, 51 distribution system 152 reserves 2, 4 distribution 17 coal powered generation 22, 23, 51, 52, 53 diurnal variation (of wind) 28 co-fi ring (with biomass) 51 double circuit 150 combined cycle gas turbine (CCGT) 12, double fed (DFIG) 22, 23, 197, 215 143 combined heat & power (CHP) 8, 9, 12 drive train compliance 139, 141 combining renewable sources 81 dump load 20 combustion 51 duty cycle 133 commutation 126 dynamic demand control 90, 93 complex power 105, 269, 270 dynamic loads 247 compressed air storage 91 dynamic simulation 172 consumer demand 56, 57, 58 continuous response 68 earth’s tilt angle 36 continuous service 64 ebb generation 44, 45 converter 97, 121, 122, 126 economic optimization 198 17 eco-tax reform 217 copper indium diselenide PV cells 241 effective head 26, 27 Coriolis 27, 43 electricity demand 55, 56, 57 Index 279 electricity distribution 10, 17, 18, 19 fl ow cells 92 Electricity Forward Agreements (EFAs) fl ywheels 92 221 forecasting demand 65, 66, 77 electricity pool 218 fossil fuels 3, 4, 8, 9, 10, 11, 13 electricity trading 218 security 13 electricity transmission 10, 17, 18, 19 four-quadrant operation 143 embedded generation 19, 175 Fourier 126 embedded generation benefi t 209 Francis turbine 26 Enercon 146 frequency control 55, 56, 59, 60, 61 energy conversion 4, 11, 12, 17 frequency response 63, 64, 68, 69, 70, 84 energy crops 52, 53 frequency response services 84 miscanthus 52 frequency trajectory 68 willow 52 friction 104, 117 energy effi ciency 9 fuel cell 12 energy security 3 fuel cost 196 56, 57, 58, 59, 69, 80, 91, fuse 17, 18 248 energy use 8 gas powered generation 22, 23, 51, 52, disparity of 3 53 environmental impact 3, 4 gasifi cation 51 equivalent circuit 104, 105 gate 123 for transformer 110, 111 GTO 123 equivalent generator 62 IGBT 123 ethanol 51 MOSFET 123 ex post pricing 223 gate closure 222 external costs 195, 204 Gauss-Seidel 168 externalities 4 generation costs 196–199, 204, 208, 210, extra high voltage (EHV) 18, 19, 150 225 generation limits 203 FACTS 161, 247 generator bus 167 Faraday’s laws 98 generator scheduling 64 fault analysis 163, 170 geographic diversity 35, 53 fault level 187 11, 14, 15, 16 fault ride through 190 global warming 4, 5, 6, 7 faults 169 governor 55, 59, 60 feed-in law 216 droop 60, 61, 63 feed-in tariffs 210, 216 set point 60, 62 fermentation 51 green electricity 218, 226, 229 fetch (for waves) 47 green pricing 209 fi eld current 99, 103 green value 226 fi eld winding 98, 99 greenhouse effect 4 fi rm power 72 gases 5, 6, 7, 8 fi ssion 22 grid 18, 19 fi xed speed wind turbine 139 grid codes 85, 191 fl icker meter 185 grid connected 15, 18, 152 fl ood generation 44 grid inertia 69, 85, 87 280 Index

Hadley Centre 6 irradiation 36, 37 harmonic distortion 185 islanding 188, 189, 247 harmonics 126, 129, 130, 185 ITER project 23 head (for hydro) 24, 25, 26, 27 IV characteristic (for PV) 38 headroom 69 heat or cold store 92 Joule defi nition 1 (footnote 2) hedging 220 heliostats 41 Kirchoff’s voltage law 106 high frequency response 70 Kyoto agreement 206 high frequency transformer 136 Kyoto protocol 6 high voltage (HV) 18, 19, 150 high voltage DC (HVDC) 153 La Rance 43, 44 HVDC 126 Lagrange multiplier 203 hydro- 2, 8, 9, 10, 11, 12, 14, large hydro 24 15, 16, 23, 24, 25, 26, 27, 53 leakage fl ux 109 hydrogen 91 leakage inductance 110 line commutated converter 126 ICGT 123 line commutated inverter 128 ideal fuel savings 76 line-drop compensation 179 ideal transformer 109 line-to neutral (phase) IGBT based converters 235, 236 voltage 157, 273 imbalance (phase-voltage) 186 line-to-line voltage 157, 274 imbalance market 222 load 55 imbalance protection 186 load angle 105, 107 impedance 266 load bus incremental cost 201, 202 load damping constant 87 inductance 258, 265 23, 32 induction generator 109, 112, 113 load fl ow 163, 167 effi ciency 116 load fl ow calculation 180, 181, inertia constant 88 182 inertial stored energy 88 load following 21, 23, 64 infi nite bus 62, 101 load sharing 61, 62 insolation 36 load shedding 67 instantaneous penetration 20 loss of mains protection 189, 190 integrated gasifi cation combined cycle loss of synchronism 108 (IGCC) 13 loss-of-load probability (LOLP) 71 integrated resource planning (IRP) 209 low voltage (LV) 18, 150 integration 18 interconnection, in power systems 57 magnetic fi eld 101 interest rate 197 magnetic fl ux 98 Intergovernmental Panel on Climate Change magnetic fl ux density 98 (IPCC) 5 magnetising current 109 intermediate plant 201 magnetising inductance 110 internalizing costs 205 magnetomotive force 99 International Energy Agency 2 marginal cost 203 inverter 123, 126, 127, 128, 130, 131 mark-to-space ratio 133 Index 281 maximum power point (for PV) 38 open cycle gas turbine 22, 53, 199, 219 medium voltage (MV) 18, 150 operating costs 195, 201, 211, 212 201 operating margin 69, 70 methane 2 operation and maintenance 196, 199 microgrids 248 optimum economic dispatch 200 microhydro 25 OptiSlip 141 moderator (for nuclear plant) 23 overcurrents 188 MPPT 38, 134 overexcitation 107 multibrid 147 over-frequency protection 67 mutual inductance 109 overhead lines 149, 150, 156, 159 nameplate rating 65 parabolic trough collector 37, 40, 42 national (NEM) parallel generator operation 61 225 part-loading 76, 80, 84 national grid 18, 58, 67, 152 64 1, 2, 3 peaking plant 201 as a fuel 4, 9 Pelamis 48, 49, 244 north sea reserves 3 Pelton turbine 26, 27 peak gas 3 penetration 19, 73, 74, 75 210 limits to 81 network data 165 related penalties 80 network losses 187 penstock 24 network reinforcement 187 permanent magnet excitation 99 neutral conductor 151, 157, 274 persistence 34 new electricity trading arrangements persistence forecasting 78 (NETA) 221 phase 261; unbalance 274 Newton-Ralphson 168 phasor 260, 261 night-storage heating 58 photovoltaics (PV) 12, 14, 16, 37, 38, 53 nitrogen 4 pitch control 32, 33 oxides 4 planning standards 246 node 164 plant cycling 22 nondispatchable sources 81 plant margin 71 normalization 117 plutonium 3 nuclear plant 22, 23, 51, 52, 53 point of common coupling (PCC) 19, 2, 9, 10, 12, 13 176 accidents 13 pole slipping 108 environmental costs 4 pole-pair 102, 103 fi ssion 3 pollution 207 pool purchase price (PPP) 219 occasional service 69 pool selling price (PSP) 220 off-peak electricity 58, 92 power angle 108 offshore wind 233, 244 power balance 55, 56, 62 oil reserves and use 2, 3, 10 power coeffi cient 31 peak oil 3 power conditioning 121 shale 2 power electronics 97, 98, 121, 122 one-line diagram 151 268 282 Index power factor correction 120, 140, 272 registered power zones (RPZs) 245 power fl ow 156, 163 released demand 63, 87, 88 power purchase agreements (PPAs) 226 reliability 70, 71, 72, 73, 76 power quality 186 reliability analysis 173 power spectrum 29 reliability impact 72 power station 10, 11, 12, 17, 18 renewables obligation (RO) 217 power system 16, 17, 18 repayment period 197 integration of renewables 18 reserve 67, 68, 69 power-frequency relationship 63 resistance 257 PQ bus 166 response (generator) 69 pricing pollution 208 responsive demand 58, 93 primary energy 1, 2 reverse power fl ow 184 conversion 12 ripple 124, 146 nuclear percentage 12 rotating magnetic fi eld (RMF) 101, 102 primary response 69 rotor wound 118 propeller turbine 26 run of the river hydro scheme 24 prospective fault current 170 running costs 195 protection 163, 169 protection relays 169 salient poles 103 pullout torque 117 scalar 261 pulsating fi eld 101 Scandinavian Nord Pool 224 pulse-width modulation (PWM) 130 scheduling error 66 pumped hydro 65, 69, 80, 91 second generation lignocellulosic (biomass) pumped storage 24, 53 crops 243 PV bus 167 secondary response 69 pyrolysis 51 self-commutated inverter 128 self-dispatch 221 quadrant diagram 270 settlement 220 quasi-sinewave inverter 129 shale gas 2 quota system 216 short circuit 169 short circuit capacity 171 radiance 36 signifi cant wave height 47 radiation intensity 36 single circuit 150 ramp up or ramp down 74 single-buyer model (SBM) 226 rate of change of frequency (ROCOF) 189 slack bus 167 rated wind speed 31 slip 113, 114, 118 rating of transformer 131 slip energy recovery 142 reactance 265 slip-rings 98, 118, 141 reaction turbine 26, 27 small hydro 25, 27 reactive power 106, 107, 111, 269 soft start 140, 141 reactive power compensation 160 soft starter 185 reactive power management 160 solar constant 36 real (active) power 116, 269 solar resource 36 rectifi cation 124, 125 solar thermal power 36, 37, 38, 40, reference bus 167 241 regional electricity companies (RECs) 218 solar tower 37, 41, 42 Index 283 specifi c speed 26, 27 tap changer 160, 161, 178 spectral density function 28 tariffs 58, 68, 92 speed-torque characteristic (for induction tertiary reserves 70 machine) 117 thermal conversion 22 spill 76 thermal limits 177, 178, 183 spot market 224 thermal plant 21, 22 square-wave inverter 128, 129 thermal power station 59 squirrel cage 112, 139 thermal store 58 stability 108 Thevenin: equivalent circuit 105, 159, stability margin 108 171 stall regulation 139 principle 275, 276 stall regulation 33 three phase generation 99, 100 standalone generation 18, 19, 20 three-phase converter 132 standalone generators 58 thyristor characteristics 123, 126, 127 stand-by generation 189 thyristor converter 126 standing losses 71 tidal barrage 42, 43, 44, 45 standing reserve 70 tidal current 45 star connection 275 tidal enhancement 43 static VAR compensation 161 tidal funnelling and resonance 43 stator 98, 99, 100 11, 12, 14, 15, 42, 43, 44, 45 stator slots 100 tidal range 43 statutory frequency limits 67 tidal stream 45, 46 steering bridge 136 tides (spring and neap) 42, 45, 46 step-up and step-down transformer 110 tip-speed ratio 32 Stern report 7 top-up and spill market 222 storage 248 tracking MPP 38 subsynchronous operation 143 transformer 98, 108, 109, 110, 111 subtransmission system 17 transformer primary and secondary 109 super capacitors 92 transformerless inverter 135 superconducting magnetic energy storage transient analysis 164, 172 (SMES) 92 transistors 123 supersynchronous operation 142 transmission line parameters 159 swing bus 167 transmission system 149, 152 switching losses 130 transmission system operator (TSO) 71 symmetrical components 170 turbulence (wind) 28, 30, 34 synchronisation 107 (tidal fl ow) 46 synchronous generator 98, 99, 100, 103 two-way generation 44 synchronous reactance 105 synchronous speed 102, 103 unbalanced analysis 168 Syngas 13 unbalanced load fl ow 163 synoptic variation (of wind) 28 unbundling 205 system balancing 70, 81 underexcitation 107 system gain 63 under-frequency relays 67 system margin 71 underground cables 150, 156 system marginal price (SMP) 219 uniform auction 219 system operator (SO) 220 uninterruptible power supply 70 284 Index unit commitment 64 Watt defi nition 1 (footnote 2) United Nations Framework Convention on Watt-hours defi nition 1 (footnote 2) Climate Change (UNFCCC) 206 47 uplift 220 near shore 48 uranium reserves 3 offshore 48 shoreline 48 variability: hydro 26 weak grid 171, 172 tidal 46, 47 Weibull distribution 30 wave power 47, 49, 50 scale factor 30 wind 28, 31, 33, 34, 35, 50 shape factor 30 variable speed drive 137 8, 9, 11, 12, 14, 15, 16, variable speed wind turbine 138, 140 19 variance (of wind variations) 28, 29 wind power forecasting 78 vector control 143 wind resource (off-shore) 28 vector shift 189 wind resource (on-shore) 27, 28 249 spectral correlation 35 voltage control 70 wind shear 28 voltage dips 184, 185 wind variability (annual, seasonal, synoptic, voltage drop calculation 157 diurnal) 33, 34, 35, 36 voltage drop compensation 156 windage 104, 117 voltage fl icker 184 world energy consumption 1, 2 voltage profi le 156 voltage regulation 161, 162 zero-up-crossing period 48 voltage rise 176, 177, 178 voltage source inverter 143 voltage steps 184 VSC-HVDC 235