WindgenerationPSCAD浙大研修班僅供參考學(xué)習(xí)學(xué)習(xí)教案課件

1、會計(jì)學(xué)1WindgenerationPSCAD浙大研修班僅供參考學(xué)習(xí)會計(jì)學(xué)1WindgenerationPSCAD浙大研修班僅供Main components第1頁/共58頁Main components第1頁/共58頁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頁/共58頁GE 3.6 MWModern Technology第2頁/Vestas V90Modern TechnologyVestas V90 3 MWWind sp

2、eed: 4 15 25 m/sDFIG :Opti-speedSpeed : 8.6 16.1 -18.4 rpmBlade Dia:90 m 第3頁/共58頁Vestas V90Modern TechnologyVesGamesa - G90Modern TechnologyAerodynamic primary brake by means of full-feathering bladesHydraulically-activated mechanical disc brake for emergencies690 V Stator4 pole machineGear ratio -

3、1:120.5 material: Pre-impregnated epoxy glass fibre with carbon fibberDFIG :Blade Dia:90 m 第4頁/共58頁Gamesa - G90Modern TechnologyAEnercon E82Modern Technology Direct drive synchronous generator Pitch control Back- to- back converter grid coupled 6- 19.5 rpm Storm control feature第5頁/共58頁Enercon E82Mod

4、ern TechnologyWind TurbineAvailable power第6頁/共58頁Wind TurbineAvailable power第6頁IMCapacitors or SVCnetworkGear boxDirect connected induction machine:No slip rings/brushes, Squirrel cage machine has a simple robust constructionLess maintenance Fixed speed operation第7頁/共58頁IMCapacitors ornetworkGear bo

5、xTorque Equation in Steady StateOperating region of the machine falls over a small speed range.No reactive power control.TorqueSpeed (pu)第8頁/共58頁Torque Equation in Steady StatEffect of varying rotor resistance in Wound Rotor MachinesTorque Equation in Steady StateRrotor increasingTypical speed varia

6、tion:+/- 5%第9頁/共58頁Effect of varying rotor resistDirect connected induction machine (variable rotor resistance):IMTo rotorControl rotor resistance with power electronics第10頁/共58頁Direct connected induction macDirect connected induction machines: Poor fault response第11頁/共58頁Direct connected induction

7、macDirect connected induction machines: Poor fault responseMachine must be tripped during faults.第12頁/共58頁Direct connected induction macSynchronous machine connected through a ac-dc-ac converter:With or without gear box Can allow variable speed operationPermanent magnet machine are used as wellSMnet

8、workGear box第13頁/共58頁Synchronous machine connected Synchronous machine: Fault response第14頁/共58頁Synchronous machine: Fault resSynchronous machine: Fault response第15頁/共58頁Synchronous machine: Fault resDouble fed induction machine:Wound rotor machine with slip rings Variable speed operation P and Q ind

9、ependent controlIMnetworkGear boxDFIG ControlsCurrent of variable frequency and magnitude are forced into the rotor windings第16頁/共58頁Double fed induction machine:WDouble fed induction machine:Fast control of P and Q Variable speed operation Optimal power tracking at low wind speeds Store kinetic ene

10、rgy in the rotating system during high windsMachine and mechanical system ratings limit operating region.Rotor crow bar protection during faultsOver speed limits. 第17頁/共58頁Double fed induction machine:FDoubly-fed Induction Machine第18頁/共58頁Doubly-fed Induction Machine第1Doubly-fed Induction Machine -

11、Stator fluxIdIqT IqQ IdId and Iq are rotor current components Controlling rotor current components Id and Iq forms the basis of the Doubly-fed Induction machine concept. Power electronic based converters are used to force rotor currents into the rotor windings to achieve desired operation.第19頁/共58頁D

12、oubly-fed Induction Machine Circuit and ModulesRotor side converter第20頁/共58頁Circuit and ModulesRotor side Position of the Flux VectorInduced voltage is the rate of change of Flux LinkageIntegral of voltage gives the flux linkage across a coil第21頁/共58頁P(yáng)osition of the Flux VectorIndEstimation of stato

13、r flux vectorImplementation is easier in the Alfa - Beta Fame.Position of the Flux Vector第22頁/共58頁Estimation of stator flux vectIraaIrbbIrccIra_refIrb_refIrc_refslpangto StatorDQRotoralfabetaABC2 to 3TransformalfabetaD and Q reference currentsGeneration of current referencesFig. 4: Final step in gen

14、eration of rotor phase reference currentsEstimation of rotor current injectionsNote: Id controls reactive power Q controls real powerCircuit and Modules第23頁/共58頁IraaIrbbIrccIra_refIrb_refIrc_hynhyT1T4Ira_refC-E+C-E+C-E+T3T6T5T2Irb_refIrc_refhyira_refira_refhyT1CPanelhysband0100.1C+E+C+E-Current-Refe

15、rence PWM Controls. Hysteresis band can be adjustedIraIrbIrc*-1CRPWM Bases firing pulse for rotor side converterCircuit and Modules第24頁/共58頁hynhyT1T4Ira_refC-E+C-E+C-E+T3Simulation ResultsControl response and the verification of performance of the modelStep change in wind speedController response to

16、 maintain Optimum tip speed ratioReduced P outputConstant Q第25頁/共58頁Simulation ResultsControl respWind Inter-connection Requirements Low voltage fault ride throughDharshana MuthumuniMay 2008第26頁/共58頁Wind Inter-connectionDharshanaWind GeneratorsInduction machines Squirrel cageWound rotorSupport of sw

17、itchable caps, SVC or STATCOMInduction machines with controls of power electronics (DFIG)Synchronous machinesPM Machines第27頁/共58頁Wind GeneratorsInduction machiIntegration of wind farms MH is considering an expansion of up to 400MW wind power Connection at either 230KV (transmission) or 66kV levels第2

18、8頁/共58頁Integration of wind farms MH iInterconnection 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 Upgrade requirement

19、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頁/共58頁Interconnection studiesOnce thInterconnection studies Dynamic (Stability)performanceFault ride throughPower, reactive po

20、wer controlAnti-islanding Transient studies:Flicker/harmonicsStarting scheme and inrushDetailed studies of controls第30頁/共58頁Interconnection studies第30頁/共5Interconnection requirements Voltage toleranceThe units should operate continuously for voltages in the range 0.9 pu to 1.1 pu at the point of int

21、erconnection. Frequency toleranceUnder- and over-frequency rangeContinuous operationShort time operation (10 minutes, 30 seconds or etc)第31頁/共58頁Interconnection requirements第3Interconnection requirements Power controlActive pitch/stall control for power adjustmentRamp down rate Reactive power contro

22、lMaintain voltage level with the power factor between a minimum of 0.95 over-excited and 0.95 under-excited第32頁/共58頁Interconnection requirements第3Interconnection requirements Voltage ride through capability to Reduce the system “shock” Under-voltage and over-voltage specs第33頁/共58頁Interconnection req

23、uirements第3Interconnection requirementsPost disturbance recovery: Post disturbance recovery of the wind units should be demonstrated through simulationsStart-up and synchronizing: Mitigating excessive voltage drops at the point of interconnection during start up/synchronization.第34頁/共58頁Interconnect

24、ion requirements第3Large wind farms have to meet very strict operating conditions set out by the system operators. One of the most important requirements is that they must remain connected and supply power to the electrical system immediately after network faults. This is called the Fault Ride Throug

25、h 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 level of power to the system. Fault Ride Through Capability requirements第35頁/共58頁Large wind farms have to meet Fault Ride Through Capabilit

26、y 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頁/共58頁Fault Ride Through Capability Fault Ride Through Capability requirementsELTRA 3 phase faults cleared in first protec

27、tion 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 80% -100% voltage for 10 s 90% -100% voltage for 3 min.第37頁/共58頁Fault Ri

28、de Through Capability 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 speed Mechanical stressThe wind turb

29、ine 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頁/共58頁The characteristic of the geneFault Ride Through Synchronous machine Field winding will act to

30、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頁/共58頁Fault Ride Through SynchronoFault Ride Through Induction machineNo reactive power control available.Voltage drop makes the shunt cap

31、acitors (or SVC) ineffective.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頁/共58頁Fault Ride Through InductionFault Ride Through DFIGOvercomes main drawbacks of the n

32、ormal Induction machinePower can be delivered at any slip (speed) through control of rotor current.Crowbar reduces effectiveness of DFIG fault recovery.第41頁/共58頁Fault Ride Through DFIGOvercFault Ride Through Equipment considerationsUnits with high inertia generally can recover faster than those with

33、 lower inertia. Less speed fluctuations. High cost Larger, heavierSpecial designs and new technology required Sophisticated control. New generator concepts第42頁/共58頁Fault Ride Through EquipmentGrid rms voltage, generator rotor speed, active power, reactive power, DC-link voltage and (ird & irq,) gene

34、rator current, response to weak voltage dip 第43頁/共58頁Grid rms voltage, generator roGrid rms voltage, generator rotor speed, active power, reactive power, DC-link voltage and (ird & irq,) generator current, response to strong voltage dip第44頁/共58頁Grid rms voltage, generator roGrid rms voltage, generat

35、or rotor speed, active power, reactive power, DC-link voltage and (ird & irq,) generator current, , response to strong voltage dip 第45頁/共58頁Grid rms voltage, generator roReference machine speed to maintain Tip- Speed ratioWhen machine speeds up, Iq_ref increases in an attempt to increase power outpu

36、t.Simple Power control loop used in the simulation第46頁/共58頁Reference machine speed to maiWind Power Wind speed distribution Short term wind speed variations Modeling wind speed System impactDharshana MuthumuniMay 2008第47頁/共58頁Wind PowerDharshana Muthumuni第Wind Speed DistributionTypical wind speed histogramRenewable and Efficient Electric Power Systems, G.M. Masters第48頁/共58頁Wind Speed DistributionTypicalShort ter