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1、会计学,1,WindgenerationPSCAD浙大研修班仅供参考学习,会计学1WindgenerationPSCAD浙大研修班仅供,Main components,第1页/共58页,Main components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,GE 3.6 MWModern Technology第2页/,Vestas V90,Modern Technology,Vestas V90
2、 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,Vestas V90Modern TechnologyVes,Gamesa - G90,Modern Technology,Aerodynamic primary brake by means of full-feathering bladesHydraulically-activated mechanical disc brake for emergencies690 V Stator4 pole mach
3、ineGear ratio - 1:120.5,material: Pre-impregnated epoxy glass fibre with carbon fibber,DFIG :Blade Dia:90 m,第4页/共58页,Gamesa - G90Modern TechnologyA,Enercon E82,Modern Technology,Direct drive synchronous generator Pitch control Back- to- back converter grid coupled 6- 19.5 rpm Storm control feature,第
4、5页/共58页,Enercon E82Modern Technology,Wind Turbine,Available power,第6页/共58页,Wind TurbineAvailable power第6页,Direct connected induction machine:,No slip rings/brushes, Squirrel cage machine has a simple robust constructionLess maintenance Fixed speed operation,第7页/共58页,IMCapacitors ornetworkGear box,To
5、rque Equation in Steady State,Operating region of the machine falls over a small speed range.No reactive power control.,Torque,Speed (pu),第8页/共58页,Torque Equation in Steady Stat,Effect of varying rotor resistance in Wound Rotor Machines,Torque Equation in Steady State,Rrotor increasing,Typical speed
6、 variation:+/- 5%,第9页/共58页,Effect of varying rotor resist,Direct connected induction machine (variable rotor resistance):,To rotor,Control rotor resistance with power electronics,第10页/共58页,Direct connected induction mac,Direct connected induction machines: Poor fault response,第11页/共58页,Direct connec
7、ted induction mac,Direct connected induction machines: Poor fault responseMachine must be tripped during faults.,第12页/共58页,Direct connected induction mac,Synchronous machine connected through a ac-dc-ac converter:,With or without gear box Can allow variable speed operationPermanent magnet machine ar
8、e used as well,第13页/共58页,Synchronous machine connected,Synchronous machine: Fault response,第14页/共58页,Synchronous machine: Fault res,Synchronous machine: Fault response,第15页/共58页,Synchronous machine: Fault res,Double fed induction machine:,Wound rotor machine with slip rings Variable speed operation
9、P and Q independent control,Current of variable frequency and magnitude are forced into the rotor windings,第16页/共58页,Double fed induction machine:W,Double fed induction machine:,Fast control of P and Q Variable speed operation Optimal power tracking at low wind speeds Store kinetic energy in the rot
10、ating 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,Double fed induction machine:F,Doubly-fed Induction Machine,第18页/共58页,Doubly-fed Induction Machine第1,Doubly-fed Induction Machine, - Stator f
11、lux,Id,Iq,T Iq,Q Id,Id 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页/共58页,Do
12、ubly-fed Induction Machine,Circuit and Modules,Rotor side converter,第20页/共58页,Circuit and ModulesRotor side,Position of the Flux Vector,Induced voltage is the rate of change of Flux Linkage,Integral of voltage gives the flux linkage across a coil,第21页/共58页,Position of the Flux VectorInd,Estimation o
13、f stator flux vector,Implementation is easier in the Alfa - Beta Fame.,Position of the Flux Vector,第22页/共58页,Estimation of stator flux vect,Estimation of rotor current injections,Note: Id controls reactive power Q controls real power,Circuit and Modules,第23页/共58页,IraaIrbbIrccIra_refIrb_refIrc_,CRPWM
14、 Bases firing pulse for rotor side converter,Circuit and Modules,第24页/共58页,hynhyT1T4Ira_refC-E+C-E+C-E+T3,Simulation Results,Control response and the verification of performance of the model,Step change in wind speed,Controller response to maintain Optimum tip speed ratio,Reduced P output,Constant Q
15、,第25页/共58页,Simulation ResultsControl resp,Wind Inter-connection Requirements Low voltage fault ride through,Dharshana MuthumuniMay 2008,第26页/共58页,Wind Inter-connectionDharshana,Wind Generators,Induction machines Squirrel cageWound rotorSupport of switchable caps, SVC or STATCOMInduction machines wit
16、h controls of power electronics (DFIG)Synchronous machinesPM Machines,第27页/共58页,Wind GeneratorsInduction machi,Integration of wind farms,MH is considering an expansion of up to 400MW wind power Connection at either 230KV (transmission) or 66kV levels,第28页/共58页,Integration of wind farms MH i,Intercon
17、nection studies,Once 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 and cost estimates (Load flow type studies:
18、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 studiesOnce th,Interconnection studies,Dynamic (Stability)performanceFault ride throughPower, reactive power controlAnti-islanding Transient studi
19、es:Flicker/harmonicsStarting scheme and inrushDetailed studies of controls,第30页/共58页,Interconnection studies第30页/共5,Interconnection requirements,Voltage toleranceThe units should operate continuously for voltages in the range 0.9 pu to 1.1 pu at the point of interconnection. Frequency toleranceUnder
20、- and over-frequency rangeContinuous operationShort time operation (10 minutes, 30 seconds or etc),第31页/共58页,Interconnection requirements第3,Interconnection requirements,Power controlActive pitch/stall control for power adjustmentRamp down rate Reactive power controlMaintain voltage level with the po
21、wer factor between a minimum of 0.95 over-excited and 0.95 under-excited,第32页/共58页,Interconnection requirements第3,Interconnection requirements,Voltage ride through capability to Reduce the system “shock” Under-voltage and over-voltage specs,第33页/共58页,Interconnection requirements第3,Interconnection re
22、quirements,Post 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页/共58页,Interconnection requirements第3,Large w
23、ind 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 Through Capability (FRT).This i
24、s 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页/共58页,Large wind farms have to meet,Fault Ride Through Capability requirements,Utility
25、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 Through Capability,Fault Ride Through Capability requirements,ELTRA 3 phase faults cleared in first protection zone 2 phase f
26、aults 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页/共58页,Fault Ride Through Capab
27、ility,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 turbine will not be
28、disconnected/stopped during this period. Higher stress on blades,Fault Ride Through Capability requirements,FRT Requirements places technical challenges and increased equipment cost.,第38页/共58页,The characteristic of the gene,Fault Ride Through Synchronous machine,Field winding will act to increase th
29、e 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 Synchrono,Fault Ride Through Induction machine,No reactive power control available.Voltage drop makes the shunt capacitors
30、 (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页/共58页,Fault Ride Through Induction,Fault Ride Through DFIG,Overcomes main drawbacks of the norm
31、al Induction machinePower can be delivered at any slip (speed) through control of rotor current.Crowbar reduces effectiveness of DFIG fault recovery.,第41页/共58页,Fault Ride Through DFIGOverc,Fault Ride Through Equipment considerations,Units with high inertia generally can recover faster than those wit
32、h lower inertia. Less speed fluctuations. High cost Larger, heavier,Special designs and new technology required Sophisticated control. New generator concepts,第42页/共58页,Fault Ride Through Equipment,Grid rms voltage, generator rotor speed, active power, reactive power, DC-link voltage and (ird & irq,)
33、 generator current, response to weak voltage dip,第43页/共58页,Grid rms voltage, generator ro,Grid rms voltage, generator rotor speed, active power, reactive power, DC-link voltage and (ird & irq,) generator current, response to strong voltage dip,第44页/共58页,Grid rms voltage, generator ro,Grid rms voltag
34、e, 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,Grid rms voltage, generator ro,Reference machine speed to maintain Tip- Speed ratio,When machine speeds up, Iq_ref increases in an attempt to increas
35、e power output.,Simple Power control loop used in the simulation,第46页/共58页,Reference machine speed to mai,Wind Power Wind speed distribution Short term wind speed variations Modeling wind speed System impact,Dharshana MuthumuniMay 2008,第47页/共58页,Wind PowerDharshana Muthumuni第,Wind Speed Distribution
36、,Typical wind speed histogram,Renewable and Efficient Electric Power Systems, G.M. Masters,第48页/共58页,Wind Speed DistributionTypical,Short term wind speed variations,Turbulence,第49页/共58页,Short term wind speed variatio,Modeling Short term wind speed variations,Wind gusts sinusoidal variation Wind ramp
37、s Noise,Gusts, ramps and noise can be superimposed onto a mean wind speed.Gusts, ramps, etc. can be defined by magnitude and duration.,第50页/共58页,Modeling Short term wind speed,Wind turbine controls should be able to function through wind speed fluctuations. Mean wind speed Wind gust Wind ramp Noise,
38、Gust,Ramp,Noise,第51页/共58页,Wind turbine controls should b,Modeling Short term wind speed variations,PSCAD allows modeling of mean wind speed, gusts, ramps and noise.,第52页/共58页,Modeling Short term wind speed,Modeling Short term wind speed variations,Different parameters can be defined by the user.,第53
39、页/共58页,Modeling Short term wind speed,Modeling Short term wind speed variations,Recorded wind speed data (speed vs time) can be used in a PSCAD simulation,第54页/共58页,Modeling Short term wind speed,Modeling Short term wind speed variations,PSCAD file read unit.,第55页/共58页,Modeling Short term wind speed,Modeling Short term wind speed variations,Tutorial: Simple grid example and the effect of variable wind.,第56页/共58页,Modeling Short term wind speed,Thank you,第57页/共58页,Thank you第57页/共58页,
