1、会计学1WindgenerationPSCAD浙大研修班仅浙大研修班仅供参考学习供参考学习第1页/共58页GE 3.6 MWWind speed:3.5 14 25 m/sDFIG:IGBT basedSpeed:8.5 15.3 rpmBlade Dia:111 m Modern Technology第2页/共58页Vestas V90Modern TechnologyVestas V90 3 MWWind speed:4 15 25 m/sDFIG:Opti-speedSpeed:8.6 16.1-18.4 rpmBlade Dia:90 m 第3页/共58页Gamesa-G90Moder
2、n TechnologyAerodynamic primary brake by means of full-feathering bladesHydraulically-activated mechanical disc brake for emergencies690 V Stator4 pole machineGear ratio-1:120.5 material:Pre-impregnated epoxy glass fibre with carbon fibberDFIG:Blade Dia:90 m 第4页/共58页Enercon E82Modern Technology Dire
3、ct drive synchronous generator Pitch control Back-to-back converter grid coupled 6-19.5 rpm Storm control feature第5页/共58页3.21vACPpm57.51012.51517.52022.5250.250.5Cp-Tip Speed0.50Cp W 0()255 W()Wind_SpeedHub_SpeedWind_Speed第6页/共58页IMCapacitors or SVCnetworkGear boxDirect connected induction machine:N
4、o slip rings/brushes,Squirrel cage machine has a simple robust constructionLess maintenance Fixed speed operation第7页/共58页TorqueT-RatedT-s CurveTorque7.368 1048.541 105T s()Trat s()0.990Speed s()Operating region of the machine falls over a small speed range.No reactive power control.TorqueSpeed(pu)第8
5、页/共58页Effect of varying rotor resistance in Wound Rotor Machines00.20.40.60.81021044104610481047.368 1041.598 105T1 s()T2 s()T3 s()T4 s()Trat s()0.990Speed s()Rrotor increasingTypical speed variation:+/-5%第9页/共58页Direct connected induction machine(variable rotor resistance):IMEcap1.0 ohm1.0 ohm1.0 o
6、hm0.7 ohmDV7330.001 ohmDADDDBDEDCDF2V729.00001 HS1Idc2.820 uFV730DIADIBDICDIDDIEDIFDECDEBDEADEFDEEDEDTo rotorControl rotor resistance with power electronics第10页/共58页RLRRL0.037 H100 MVA Transformer33/230 kV,Z=0.1 pu55 km line230 kV230 kV Eq.sourceStation AWind Farm#1#2VASTLI MWRrotor+Rrotor+Rrotor+Ex
7、ternal rotor resistance1.004Stot0.037 HBRKTimedBreakerLogicOpent0BRK-0.50.02Direct connected induction machines:Poor fault response第11页/共58页Direct connected induction machines:Poor fault responseMachine must be tripped during faults.Direct connected IM response to a fault 1.50 2.50 3.50 4.50 5.50 6.
8、50 .0.20 1.00 puVrms0.9900 1.0400 puW0.00 0.20 0.40 0.60 0.80 1.00 1.20 puP1-1.50-1.00-0.50 0.00 0.50 1.00 1.50 puQ1第12页/共58页Synchronous machine connected through a ac-dc-ac converter:With or without gear box Can allow variable speed operationPermanent magnet machine are used as wellSMnetworkGear bo
9、x第13页/共58页RLRRL0.037 H100 MVA Transformer33/230 kV,Z=0.1 pu55 km line230 kV230 kV Eq.sourceStation AWind Farm#1#2STe3AVTmTm0Ef0TmwEfIfVTIT3IfEfEf0VrefExciter_(AC1A)Vref0S/HinholdoutL2NWVA0.037 HBRKBRK0.02TimedBreakerLogicOpent0Synchronous machine:Fault response第14页/共58页Synchronous machine:Fault resp
10、onseMain:Graphs 0.0 2.0 4.0 6.0 8.0 10.0 12.0 .0.00 0.20 0.40 0.60 0.80 1.00 1.20 1.40 puVrms0.9940 0.9960 0.9980 1.0000 1.0020 1.0040 1.0060 puW0.04.50 yEfMain:Graphs 1.0 3.0 5.0 7.0 9.0 11.0 .0.10 0.20 0.30 0.40 0.50 0.60 0.70 0.80 0.90 1.00 puPg0.00 0.50 1.00 1.50 2.00 2.50 3.00 3.50 4.00 puQg第15
11、页/共58页Double fed induction machine:Wound rotor machine with slip rings Variable speed operation P and Q independent controlIMnetworkGear boxDFIG ControlsCurrent of variable frequency and magnitude are forced into the rotor windings第16页/共58页Double fed induction machine:Fast control of P and Q Variabl
12、e speed operation Optimal power tracking at low wind speeds Store kinetic energy in the rotating system during high windsMachine and mechanical system ratings limit operating region.Rotor crow bar protection during faultsOver speed limits.第17页/共58页G4BUS 8 IstatorCTRLSTLI MWV&Controls&ControlsGRIDCon
13、verterConverterGENERATORGABCSABCS2TMODETIMEWindTRQWind ParkTmCpVwWm0.28W4WspdChange wind speed fom 12 to 10.5 m/sD+F+Vw.3-3第18页/共58页-Stator fluxIdIqT IqQ IdId and Iq are rotor current componentsq Controlling rotor current components Id and Iq forms the basis of the Doubly-fed Induction machine conce
14、pt.q Power electronic based converters are used to force rotor currents into the rotor windings to achieve desired operation.第19页/共58页G4BUS 8 IstatorCTRLSTLI MWV&Controls&ControlsGRIDConverterConverterGENERATORGABCSABCS2TMODETIMEWindTRQWind ParkTmCpVwWm0.28W4WspdChange wind speed fom 12 to 10.5 m/sD
15、+F+Vw.3-3Ecap10000.0EcaprefBRKGAIrcIrbT1T1D2T1T2D1T2D2T1D1T2T4T5T6T3ErcIraErbEraGBGCT2D1D21.0VCR-PWM basedRotor-side converterRotor side converter第20页/共58页VtddttVdInduced voltage is the rate of change of Flux LinkageIntegral of voltage gives the flux linkage across a coil第21页/共58页VbetaVsmagVcVaIsaC-
16、D+IsaVbC-D+phisyphisxXYYr to pXmagphiphsmagGsT1+sT*0.467*0.467ValfaGsT1+sT1sT1sTphisABC3 to 2 Transformalfabeta*0.467IsaC-D+C+D-AngleResolverinoutphisrotor_angleVery important signal-present location =of rotating stator fluxdetermining the relative difference between stator flux and rotor position f
17、or resolving therotor currentsIdentification of main stator flux by integrating stator voltageafter removal of resistive drop.The washout filter removes any dc component from the integrated flux without significantly ffecting the phaseslpangEstimation of stator flux vectorImplementation is easier in
18、 the Alfa-Beta Fame.第22页/共58页IraaIrbbIrccIra_refIrb_refIrc_refslpangto StatorDQRotoralfabetaABC2 to 3TransformalfabetaD and Q reference currentsGeneration of current referencesFig.4:Final step in generation of rotor phase reference currentsEstimation of rotor current injectionsNote:Id controls react
19、ive power Q controls real powerCircuit and Modules第23页/共58页hynhyT1T4Ira_refC-E+C-E+C-E+T3T6T5T2Irb_refIrc_refhyira_refira_refhyT1CPanelhysband0100.1C+E+C+E-Current-Reference PWM Controls.Hysteresis band can be adjustedIraIrbIrc*-1CRPWM Bases firing pulse for rotor side converter第24页/共58页1111.51212.5
20、1313.51212.51313.5(a)Vwind(m/s)1111.51212.51313.51.15(b)Speeds(pu)1111.51212.51313.5200300400500(c)PG4(MW)1111.51212.51313.5100150200(d)QG4(MVar)Time (s)refoutControl response and the verification of performance of the modelStep change in wind speedController response to maintain Optimum tip speed r
21、atioReduced P outputConstant Q0102030405000.10.20.3Cp Wv 10()Cp Wv 12()Cp Wv 14()Wv()第25页/共58页Wind Inter-connectionq Requirementsq Low voltage fault ride throughDharshana MuthumuniMay 2008第26页/共58页Wind GeneratorsInduction machines Squirrel cageWound rotorSupport of switchable caps,SVC or STATCOMIndu
22、ction machines with controls of power electronics(DFIG)Synchronous machinesPM Machines第27页/共58页Integration of wind farmsWind FarmwsG Tl1 TWind GeneratorswsGRTWind Generator 3wsG 230 kV BusRLRRL#1#2Wind FarmwsG 33 kV Bus#1#2 Loads LV Bus MH is considering an expansion of up to 400MW wind power Connec
23、tion at either 230KV(transmission)or 66kV levels第28页/共58页Interconnection studiesOnce the potential wind sites have been selected,studies are typically carried out to determine the following aspects:Direct connection cost estimates and connection scheme-breaker terminations or new station Network Upg
24、rade requirement and cost estimates(Load flow type studies:DC power flow or AC power flow to investigate overloading elements,abnormal voltages and potential impacts on tie line flows)第29页/共58页Interconnection studies Dynamic(Stability)performanceoFault ride throughoPower,reactive power controloAnti-
25、islanding Transient studies:oFlicker/harmonicsoStarting scheme and inrushoDetailed studies of controls第30页/共58页Interconnection requirements Voltage toleranceoThe units should operate continuously for voltages in the range 0.9 pu to 1.1 pu at the point of interconnection.Frequency toleranceoUnder-and
26、 over-frequency rangeoContinuous operationoShort time operation(10 minutes,30 seconds or etc)第31页/共58页Interconnection requirements Power controloActive pitch/stall control for power adjustmentoRamp down rate Reactive power controloMaintain voltage level with the power factor between a minimum of 0.9
27、5 over-excited and 0.95 under-excited第32页/共58页Interconnection requirements Voltage ride through capabilityo to Reduce the system“shock”oUnder-voltage and over-voltage specs第33页/共58页Interconnection requirementsPost disturbance recovery:oPost disturbance recovery of the wind units should be demonstrat
28、ed through simulationsStart-up and synchronizing:oMitigating excessive voltage drops at the point of interconnection during start up/synchronization.第34页/共58页Large wind farms have to meet very strict operating conditions set out by the system operators.One of the most important requirements is that
29、they must remain connected and supply power to the electrical system immediately after network faults.This is called the Fault Ride Through Capability(FRT).This is to ensure the stable operation of the power system during high wind periods when the wind generation could be supplying a significant le
30、vel of power to the system.Fault Ride Through Capability requirements第35页/共58页Fault Ride Through Capability requirementsUtility Grid Codes define the FRT requirement that the Wind Farm owner has to conform.These standards are not uniform an vary from one system owner to he other.第36页/共58页Fault Ride
31、Through Capability requirementsELTRA-3 phase faults cleared in first protection zone-2 phase faults with unsuccessful re-close 100-50 ms.-Faults with 60%-80%voltage-1-0 s.-Restrictions on Crow-Bar operation to maintain control capabilities.NEMMCO(Australia)-Zero voltage for up to 175 ms followed by-
32、80%-100%voltage for 10 s-90%-100%voltage for 3 min.第37页/共58页The characteristic of the generator plays an important role.Synchronous Induction DFIGThe machine will not be tripped during the specified fault duration.Larger winding currents for a longer duration Larger magnetic forces Higher rotation s
33、peed Mechanical stressThe wind turbine will not be disconnected/stopped during this period.Higher stress on bladesFault Ride Through Capability requirementsFRT Requirements places technical challenges and increased equipment cost.第38页/共58页Fault Ride Through Synchronous machine Field winding will act
34、 to increase the terminal voltage.This will help push more power to the network during the recovery period.Fast response of he field circuit helps fault recovery.第39页/共58页Fault Ride Through Induction machineNo reactive power control available.Voltage drop makes the shunt capacitors(or SVC)ineffectiv
35、e.Speed(slip)increases during the fault.Increased slip causes more reactive power to flow into machine.This causes a voltage drop after fault and reduce power output capability.第40页/共58页Fault Ride Through DFIGOvercomes main drawbacks of the normal Induction machinePower can be delivered at any slip(
36、speed)through control of rotor current.Crowbar reduces effectiveness of DFIG fault recovery.第41页/共58页Fault Ride Through Equipment considerations-Units with high inertia generally can recover faster than those with lower inertia.-Less speed fluctuations.-High cost-Larger,heavier-Special designs and n
37、ew technology required-Sophisticated control.-New generator concepts第42页/共58页Main,DGIF_Controls:Graphs 0.60 3.00 .0.650 1.100 KV(kV)Vgrms_pu1.0900 1.1150 speed_puw puWref_0.0400 KWPg-25.0 20.0 KWQgQg_ref9.0000 10.0000 puEcap1.0 8.0 KAIrd38.0 56.0 KAIrqGrid rms voltage,generator rotor speed,active po
38、wer,reactive power,DC-link voltage and(ird&irq,)generator current,response to weak voltage dip 第43页/共58页Grid rms voltage,generator rotor speed,active power,reactive power,DC-link voltage and(ird&irq,)generator current,response to strong voltage dipMain,DGIF_Controls:Graphs 0.60 3.00 .0.650 1.100 KV(
39、kV)Vgrms_pu1.0900 1.1150 speed_puw puWref_0.0400 KWPg-25.0 20.0 KWQgQg_ref9.0000 10.0000 puEcap1.0 8.0 KAIrd38.0 56.0 KAIrq第44页/共58页Main,DGIF_Controls:Graphs 0.60 3.00 .0.20 1.10 KV(kV)Vgrms_pu1.090 1.160 speed_puw puWref_0.0400 KWPg-40.0 20.0 KWQgQg_ref9.0000 10.0000 puEcap-2.00 8.00 KAIrd38.0 56.0
40、 KAIrqGrid rms voltage,generator rotor speed,active power,reactive power,DC-link voltage and(ird&irq,)generator current,response to strong voltage dip 第45页/共58页VwWind speed signalG1+sTWref_NDN/D10.909OptimalTip Speed RatioSpeed ReferenceIPD+F-WpuSpeed ReferenceWref_G1+sT Iq_refReference machine spee
41、d to maintain Tip-Speed ratioWhen machine speeds up,Iq_ref increases in an attempt to increase power output.Simple Power control loop used in the simulation第46页/共58页Wind Powerq Wind speed distributionq Short term wind speed variationsq Modeling wind speedq System impactDharshana MuthumuniMay 2008第47
42、页/共58页Renewable and Efficient Electric Power Systems,G.M.Masters第48页/共58页Short term wind speed variationsTurbulence第49页/共58页Modeling Short term wind speed variations Wind gusts sinusoidal variation Wind ramps NoiseGusts,ramps and noise can be superimposed onto a mean wind speed.Gusts,ramps,etc.can b
43、e defined by magnitude and duration.第50页/共58页Wind turbine controls should be able to function through wind speed fluctuations.Mean wind speed Wind gust Wind ramp Noise Main:Graphs 0.0 1.0 2.0 3.0 4.0 5.0 6.0 7.0 8.0 9.0 10.0 .2.0 4.0 6.0 8.0 10.0 12.0 14.0 y Wind_speed Main:Graphs 0.75 1.00 1.25 1.5
44、0 1.75 2.00 2.25 2.50 2.75 3.00 .8.00 8.50 9.00 9.50 10.00 10.50 11.00 y Wind_speed Main:Graphs 0.420 0.440 0.460 0.480 0.500 0.520 0.540 0.560 0.580 0.600 .8.00 8.50 9.00 9.50 10.00 10.50 11.00 y Wind_speedGustRampNoise第51页/共58页Modeling Short term wind speed variationsVwWind SourceGustMeanRampNoise
45、TmVwBetaWPWind TurbineMOD 2 TypeWind TurbineGovernorWmBetaPgMOD 2 Type PSCAD allows modeling of mean wind speed,gusts,ramps and noise.第52页/共58页Modeling Short term wind speed variations Different parameters can be defined by the user.第53页/共58页Modeling Short term wind speed variations Recorded wind sp
46、eed data(speed vs time)can be used in a PSCAD simulation0246810050010001500第54页/共58页Modeling Short term wind speed variations PSCAD file read unit.第55页/共58页Modeling Short term wind speed variationsTutorial:Simple grid example and the effect of variable wind.第56页/共58页Thank youPgenIarIbrIarIrIrPitchAn
47、gleVw39.0LambdaS1*1.623dwmD+F+wmNDN/DTewmwg1.0wgslipslipVw0.660.04Beta_OptBeta_OptLambda188.4956beta_starPitch_AngleCpIrefPitchAngleNDN/DSlipCalculationwgwsSlipxyzxyVT80_EMTDC.txtTeHub SpeedRotorCurrentComputerwrIarIbrIrRotorCurrentModulatorIrefIrSPowerControlslipoptPsetI_refP_actPitchControllerbeta*betaSpeedControlVws_refoptslipCp LambdaHub SpeedOptimum Pitch AngleSilp第57页/共58页
