PSCAD电力系统次同步振荡分析介绍课件.ppt

1、Introduction to Sub Synchronous Effects in Power NetworksDharshana MuthumuniManitoba HVDC Research CentreOutline-Electrical resonance in the network-Super synchronous resonances-Sub synchronous resonances-Series compensation-Mechanical system of a turbine-generator-Mechanical system resonances-Model

2、ing-Machines and network-Mechanical system-SSR Issues-Induction generator effect-Torsional interactionsNetwork Electrical Characteristics Frequency response of the network1.00.150.0BRKR=0Ea2Ia2BRKTimedBreakerLogicOpent0L0.1C1 106f12 L Cf503.292Network Electrical Characteristics Frequency response of

3、 the network Resonance points.Damping is due to loads and losses.Multiple resonance points in a complex power network.Location of the disturbance.Network Electrical Characteristics Frequency response of the networkGEN10GEN1GEN2GEN4GEN5GEN6GEN7GEN8GEN9TRNS2TRNS4TRNS5TRNS6TRNS7TRNS8TRNS9TRNS10BUSBus 3

4、0BUSBus 2BUSBus 37BUSBus 9BUSBus 31BUSBus 6BUSBUSBus 34Bus 20BUSBUSBus 33Bus 19BUSBus 35BUSBUSBus 22Bus 38Bus 29BUSBus 36BUSBus 23BUSBUSTL2-1Bus 1Bus39BUSTL9-39BUSBus 8TL8-9BUSBus 7TL7-8TL5-8BUSBus 5TL6-7BUSBus 4TL4-5BUSBus 3TL3-4TL2-3Bus 25TL2-25TL3-18BUSBus 18BUSBus 26TL25-26BUSBus 28TL26-28TL26-2

5、9TL28-29BUSBus 17TL17-18TL17-27BUSBus 27TL26-27GEN3TRNS3BUSBus 32BUSBus 10BUSTL10-11Bus 11TL6-11BUSBus 12TRNS11BUSBus 13TRNS12Bus 14TL13-10Bus 15BUSBus 16TL16-15TL16-17BUSBus 24TL24-16TL16-19BUSBus 21TL21-22TL22-23TL24-23TL1-39BUSBUSTL15-14TL14-13BUSVBUS5VBUS26VBUS28VBUS15VBUS17VBUS16VBUS14VBUS21VBU

6、S24VBUS1VBUS9VBUS8VBUS31VBUS30VBUS2VBUS37VBUS25VBUS6VBUS39VBUS12VBUS11VBUS13VBUS32VBUS34VBUS33VBUS20VBUS19VBUS38VBUS10VBUS29VBUS4VBUS3VBUS27VBUS36VBUS23VBUS35VBUS22VBUS18TL4-14TL5-6TL16-21loadloadloadloadloadloadloadloadloadloadloadloadloadloadloadloadloadloadloadSlack BusTRNS13System Response to a

7、Disturbance Oscillations at natural frequency Multiple resonanceIa20.1Ea1Ia11.0BRKR=05.00.041.0System Response to a DisturbanceIa20.1Ea1Ia11.0BRKR=05.00.041.0500 Hz1000 HzMain:Graphs 0.160 0.180 0.200 0.220 0.240 0.260 0.280 .-40 40 yEa1-0.150-0.100-0.050 0.000 0.050 0.100 0.150 yIa1-0.040 0.040 yIa

8、2System Response to a DisturbanceSub Synchronous ResonanceAddition of power system components cause the resonance points to shift.A resonance point at a frequency below the system frequency is termed Sub Synchronous.Addition of series compensation can cause sub synchronous resonance points.Sub Synch

9、ronous ResonanceProblems associated with Sub Synchronous Currents and voltages(SSR Problems)Self excitation of Machines(感应发电机效应)Interaction of the electrical network with the mechanical(shaft)system of a turbine generator.Torsional Interaction（扭振相互作用 small disturbance）Torque Amplification（扭矩放大 large

10、 disturbance）Interference with Power system controls(PSS,Governors etc.)1.00.11.00.11.00.1IsInduction Generator Effect Basic Theory Induction generator Slip,Effective Negative ResistanceRsLsRrLr(1-s)/sRrSWsWrWsRrsEffective rotor resistance Negative for generator action If the negative resistance is

11、greater than the total network resistance seen from the rotor,self-excitation will occur.Voltage amplification.Induction Generator Effect Simulation ExampleS/HinholdoutcfldvfldMactivtelecSystem Group0.43230.03454830.0linevTimermcswInitial Angle of source=-14.9 deg.Initial Ramp up time =0.2 sec.Machi

12、ne enabled at =1.1 sec.Y winding leads the deltawinding by 30 degrees.Initial Angle of source=-3.813 deg.Initial Ramp up time =0.2 sec.Source Magnitude =477.8 kV.Tmstdy6.0832VMac3 PhaseRMSVHIHVCABC-GTimedFaultLogicISW0.05178VISTeTmEf0TmwEfIfw#1#2Ifa376.99Z(f)0.0 -100 HzMagPhdc(31)(31)F F TF=5 HzVI1M

13、agPhdc(31)(31)F F TF=5 HzVMac121.9771.0 This system has a electrical resonance point at around 40 HzInduction Generator Effect Simulation ExampleS/HinholdoutcfldvfldMactivtelecSystem Group0.43230.03454830.0linevTimermcswInitial Angle of source=-14.9 deg.Initial Ramp up time =0.2 sec.Machine enabled

14、at =1.1 sec.Y winding leads the deltawinding by 30 degrees.Initial Angle of source=-3.813 deg.Initial Ramp up time =0.2 sec.Source Magnitude =477.8 kV.Tmstdy6.0832VMac3 PhaseRMSVHIHVCABC-GTimedFaultLogicISW0.05178VISTeTmEf0TmwEfIfw#1#2Ifa376.99Z(f)0.0 -100 HzMagPhdc(31)(31)F F TF=5 HzVI1MagPhdc(31)(

15、31)F F TF=5 HzVMac121.9771.0Observe the following Effect when the system resistance is lowered Effect of resistance on damping Rotor electrical time constants HarmonicsInduction Generator Effect Simulation results1.00 2.00 3.00 4.00 .0.750 0.800 0.850 0.900 0.950 1.000 Machine Output Volts p.u.-1.50

16、-1.00-0.50 0.00 0.50 1.00 1.50 Capacitor Volts,A-3.0-2.0-1.0 0.0 1.0 2.0 3.0 Machine Current,A,out+1.00 2.00 3.00 4.00 .0.700 0.750 0.800 0.850 0.900 0.950 1.000 1.050 1.100 Machine Output Volts p.u.-2.00-1.50-1.00-0.50 0.00 0.50 1.00 1.50 2.00 2.50 Capacitor Volts,A-4.0-3.0-2.0-1.0 0.0 1.0 2.0 3.0

17、4.0 Machine Current,A,out+R=6 OhmsR=2 OhmsTerminal voltageVmac20.00.08 5.4099577301940 HzTorsional Interaction and Torque Amplification.Interaction of the electrical and mechanical systems Machine Model Detailed model is required(same as for Induction generator effect)Second q-axis damper winding mo

18、del for Thermal units Eddy current effects Shaft Model Lumped Mass Model is not sufficient.Shaft Model.T12TeJ1tw1ddD1w1D12w1w1tT12k1221 kk1221TeD1w1J1tw1ddtShaft Model.2 H1tw1ddk1221Te k2 H2tw2ddTLpk2332k1221Lp2 H3tw3ddTHpk2332HpNatural modes of the shaft systemEigen value AnalysisDamping omittedTor

19、sional Interaction and Torque Amplification.Natural modes of the shaft systemEigen value AnalysisRPM3000F50.0MVA354.35K239.12107Conversion Constants from MKS to P.U.:MKS2SEC2 RPM6022 MVA106MKS2PUPR2 RPM60MVA 106H2 H10002 H20002 H3MKS2SECH0.4180006.8240001.671KK12K120K12K12K23K230K23K23MKS2PUPRK37.38

20、537.385037.385118.24280.856080.85680.856Eigenvalue Analysis with Normalization so Largest Element in a Column is 1:Q1eigenvecs H1KQM1max Q11 Leigenvals H1KQM2max Q12 QM3max Q13 QQ11 1QM1Q12 1QM1Q13 1QM1Q11 2QM2Q12 2QM2Q13 2QM2Q11 3QM3Q12 3QM3Q13 3QM3Analysis of Turbine Shaft System:Inertia Constants

21、(kg.m2):Spring Constants(kg.mm/rad):H11500(HP Turbine)K12D4.3 109H224500(LP Turbine)H36000K23D9.3 109Generator()Ga9.8065(m/sec2)K12K12D.001Ga(Gravitational Constant)(N.m/rad)K23K23D.001GaBasic Ratings:K124.217107 Simple Mathcad/Matlab analysis can identify the torsional modes.Network frequency scan will identify the electrical resonancesTorsional Interaction and Torque Amplification.Simulation Examples Simple 3 Mass Shaft IEEE SSR Benchmark model