例子pscad研討會(huì)-科學(xué)軟件網(wǎng)fundamentals of emt part

1、Dharshana Muthumuni, Ph.D, P.EngManitoba HVDC Research CentreWinnipeg, ManitobaCanadaFundamentals of Electro-Magnetic Transients in Electric Networks and EMT ProgramsTypical Applications Black Start Studies Faults and Protection Equipment failure analysisGetting a power system back into operation af

2、ter black-out- is not an easy task and should be carefully planned (Black start restoration plans)Key issues: Can we energize lines , transformers and loads through available generating units? System has very little damping due to low load. Resonance issuesStudy Approach Restoration steps are determ

3、ined and documented step by step System single line drawings are used to illustrate each step Electrical studies are necessary to verify that the selected restoration actions (steps) can be implemented without damaging equipmentSystem Black Start restoration StudiesEngTCPSTLine_02_02TLine_02_01TLine

4、_02_03row1TLine_02_05TLine_02_07TLine_02_08TLine_02_09QILWAHMIKHWAHNAMERAAD DUQAHQUNFUDAH TOWNQUNFUDAH CPSTHORYBANTLine_01_01TLine_01_07TLine_01_06TLine_01_05row1TLine_01_04TLine_01_08TLine_01_09TLine_01_10TLine_01_11TLine_01_12TLine_01_13TLine_01_15TLine_01_17TLine_01_16SUFFAHSABTAL JARAJAL BIRKMAJ

5、ARDAHMUHAIL NORTHMUHAIL26.326 km53.618 km38 km9 km95 km67 km36 km49 km68 km47 km67 km100 km44 km94 km82 km86 km72 kmEtcpsE1EtcpsE2#1#2BRKGTimedBreakerLogicOpent0IquntIquntP+jQ#1#2P+jQTLine_01_03P+jQ#1#2P+jQ#1#2TLine_01_02#1#2P+jQ#1#2P+jQTLine_02_04TLine_02_06TLine_01_14P+jQ#1#2TLine_02_05_2P+jQ#1#2#

6、1#2P+jQE3P+jQ#1#2P+jQ#1#2E2E3BRKGE1TLine_01_aBil JurshiTLine_01_baEaVTIT3IfEfEf0VrefExciter (ST3A)Vref0Ef0E132P = 325.6Q = 227V = 0.9996VAEfWL2NS2MTIMETIMES2MS / HinholdoutTM01.0STe3AVTmTm0Ef0TmwEfIfNeuclear plant : Con.P15.73182Q13.91242#1#2D-F+W*13.333G1 + sTD-F+G1 + sTS / HinholdoutTM0L2NIa#1#2P+

7、jQL2NTM01S / HinholdoutG1 + sTD-F+G1 + sT*13.333W1D-F+STe3AVTmTm0Ef0TmwEfIf1.0TM01S / HinholdoutS2MW1Ef0VTIT3IfEfEf0VrefExciter (ST3A)Vref0#1#21 unit = 150 MVA1 unit 80 MVASystem Black Start restoration StudiesTransformer energizing:Energizing a transformer from the HV side.Transformer Energizingx0.

8、00 0.50 1.00 1.50 2.00 2.50 3.00 . . .-1.50 -1.00 -0.50 0.00 0.50 1.00 1.50 PUE_49900-1.50 -1.00 -0.50 0.00 0.50 1.00 1.50 2.00 kAItfTransformer Energizingx0.00 0.10 0.20 0.30 0.40 0.50 0.60 0.70 0.80 0.90 1.00 . . .-1.50 -1.00 -0.50 0.00 0.50 1.00 1.50 PUE_49900-1.50 -1.00 -0.50 0.00 0.50 1.00 1.50

9、 2.00 kAItfSystem Black Start restoration StudiesTransformer energizing:Energizing a transformer from the HV sideAnalog GraphFrequency0 100 200 300 400 500 600 . . .0.0 0.2k0.4k0.6k0.8k1.0k1.2k1.4k1.6kOhms|Z+|(ohms)TLine1TLine2BRK#1#3#20.1RLRRLXXXXTLine2280 km220 kmSystem Black Start restoration Stu

10、diesLong line energizing through small generating units Self excitation issues Sudair Bus#1#2Ia1Ia2Ib1Ib2BRKGTimedBreakerLogicClosedt0BRKGBRKLBRKLTimedBreakerLogicOpent0STe3AVTmTm0Ef0TmwEfIfTM0S / HinholdoutS2MTIMETIMES2ML2NWEf1e6VAEsovSteam_Tur_1wTm1Tm2WrefCvwWrefCv Steam Gov 4B+F+VswPPSS2B P1W TL_

11、SUD_P.Ef0VTIT3IfEfEf0VrefExciter (ST4B)Vref0Ea1.0 x1.50 2.00 2.50 3.00 3.50 4.00 4.50 5.00 5.50 . . .0.00 0.20 0.40 0.60 0.80 1.00 1.20 PU Vrms_machine-1.50 -1.00 -0.50 0.00 0.50 1.00 1.50 Ea - Machine terminal-1.50 -1.00 -0.50 0.00 0.50 1.00 1.50 2.00 PU Esov - PP9 Bushing-1.50 -1.00 -0.50 0.00 0.5

12、0 1.00 1.50 PU Ef - Machine field voltage0.99982 1.00002 WSystem Black Start restoration StudiesComplex Protection IssuesTransient simulations are required to analyze CT saturation DC offset in fault currents Generate test waveforms for relay testing Power quality issuesCT Response 0.00 0.10 0.20 0.

13、30 0.40 0.50 0.60 . . .-60 -40 -20 0 20 40 60 80 yIsec-0.25 2.25 yB-5.0k35.0kyHMinor B-H loop formationCT response to a DC offset in fault currentFaults and ProtectionComplex Protection IssuesMutual effect on near-by lines during faultsFaults and Protection#1#2P = 2.269Q = 1.796V = 1.014VAB2-.T230kV

14、 3H6300kmB4-.T230kV 3H6300kmB4-.T230kV 3H6300kmP = -1.69Q = 0.3878VAP = 0.3119Q = -0.2389VAP = -0.306Q = -0.2781VARating: 250 MVARating: 250 MVARating: 250 MVAP+jQ180.0 MVARP+jQP = 3Q = -1.076V = 1.057VAUsUrB7-.T345kV 3H6600kmRating: 500 MVA#1#2P+jQP = -1.976Q = 0.3429V = 0.9951VAP = 0.2669Q = -0.62

15、38VA#1#2P = 2.573Q = 1.393V = 1.028VAbus4 compensatorB3-B4-1T230kV 3H6100kmB3-B4-2T230kV 3H6100kmRating: 250 MVARating: 250 MVA160.0 MVARP+jQ#1#2P = 4.935Q = 1.679V = 1.021VAP+jQ80.0 MVARBus 2Bus 10Bus 5Bus 4Bus 6Bus 12Bus 7Bus 8Bus 3Bus 11P = 179.9Q = -9.269VAB11aFaults and Protection PSCAD simulat

16、ions studies are used to select, design or verify:Relay settings on critical lines and equipmentIssues due to CT and VT non linear behaviourCCVT resonance problemsRelay malfunction due to CT saturation Relay settings under unbalanced network conditionsRelay settings in complex situations (i.e. serie

17、s compensated lines)Response to harmonics.Settings for travelling wave relays.Power swing protection Black start conditionsProtection of emerging technology including wind farms, FACTS devices, etc.CT SaturationRRLRRLA-GTimedFaultLogicVabcIabcTLine1TTLine2TTLine3TP+jQ200 km long 230 kV transmission

18、line simulated in twosegments to facilitate application of faults at different point on the line.75 km long second 230 kV transmission line Fault at 0.4876sand 0.49167sApply faults at different inception angles and observe the initial DC exponential In the fault currentMain : Graphs 0.400 0.450 0.50

19、0 0.550 0.600 0.650 0.700 . . .-200 200 VVabc-30.0 15.0 I secIa_sec-5.0 3.0 I priIabc-2.00 0.25 Flux denBLoss (reduction) of secondary current due to CT core saturationSaturation is a result of the DC component in the fault currentThe DC exponential in the fault current will force the CT core flux t

20、o move in one directionThis can lead to saturation and a resultant loss of secondary current to the relayCT secondary burden influences the saturation of the CT coreCT SaturationRRLRRLPQBRK1-0.001815 MVAR0.02649 MWP1Q1ABTimedFaultLogicVabcDistance BrkStatVr(abc)Ir(abc)TripRelayVsabcIsabc123Sa1Sa1Sb1

21、Sc1SabcTripBRK1TIMEABCtrlCtrl =1Ctrl ModeIabcTLine1TTLine2TManual On/OffBlock breaker operatonduring intial .05sTLine3TP+jQABTimedFaultLogic75 km long second 230 kV transmission line Fault at 0.4876sand 0.49167sMain : Breaker ControlCtrl Mode1Manual AutoManual On/Off0CloseOpenDistance relay operatio

22、n can be affected by CT saturationCT SaturationMal-operation of an earth fault relay during transformer energising.Inrush current caused unequal saturation of the 3 CTs, resulting in a burden currentPSCAD case:Earth_fault_relay.psc(required ThreCt.psl and a custom Fortran file)CT SaturationCT of pha

23、se A saturated during energising of a single phase transformer in a distribution feederMain,CT1 : Graphs 0.00 0.20 0.40 0.60 0.80 1.00 . . .-2.0 12.0 Ib (A)Ib-0.25 2.00 B (T)B1-20 120 Ia (Amps)IaCT SaturationSeries Compensated LineProtection of Series Compensated Lines Model DevelopmentLines , Line

24、arrester, Series capacitors etc.One series capacitor is modeled in detailBypass breakersArrestersBypass breaker logic based on fault current level and arrester (parallel with capacitor) energy Modeling ValidationNetwork equivalent sources based on positive and zero sequence impedancesVoltage magnitu

25、de and phase determine the power flow in linesValidate model with power flow and short circuit current comparison with expected steady state resultsStudies must be done under different power flow conditionsL1CL1TL2CL2TTYL1_aTStation AStation BStation CStation DStation ETYL1_bTTYL2_aTTYL2_bTTYL3_aTTY

26、L3_bTYATPAL1TPAL2TPAL3TYPTRLVFPhRRLfreqRLVFPhRRLfreqRLVFPhRRLfreqRLVFPhRRLfreqRLVFPhRRLfreqP = -103.6Q = 541.8VAVcuaVcua60.0freqP_CUAQ_CUAP = -394.2Q = 576.7VAP = -63.92Q = 297VAP = 503.9Q = 153.6VAP = 269.7Q = 323VATimedFaultLogicA-GITYL1ITYL1TimedBreakerLogicClosedt0BT3TimedBreakerLogicClosedt0BY3

27、BY3E1E2BT3System modelSeries Compensated LineSeries capacitor modeling detailsaL1 - Segment 1BRKN310.0402 ohm820.5e-6 H88.417 uFXc= 30 OhmC= 1/(377.30) = 88.41uFSeries Compensated LineComplexities in Series Compensated Line Protection 1.150 1.200 1.250 1.300 1.350 1.400 1.450 . . .-300 300 E1E1-300

28、400 E2E2-20.0 25.0 ITYL1ITYL10.01.00 Ba1 signalBa1Complex voltage and current waveforms the relays must deal with during a faults close to the capacitorsSeries Compensated LineSeries Compensated 500 kV Line, Model BenchmarkingFault Current Contribution of MachinesDetailed emt type simulation is the

29、only way to accurately models the nature of fault current waveforms of different machines.With the increased popularity of Induction generator based wind farms, the accurate estimate of fault contribution of complex induction machine generation concepts has e very important.e.g. Fault contribution o

30、f a DFIG is complex to analyse on simple fault analysis programs.Induction Machine 2.40 2.60 2.80 3.00 3.20 3.40 3.60 3.80 4.00 4.20 . . .-60 -40 -20 0 20 40 60 80 Fault currentI1Main : Graphs 0.0 1.0 2.0 3.0 4.0 5.0 6.0 7.0 8.0 9.0 10.0 . . .-20 -10 0 10 20 30 40 50 yIscInduction Machine- Current d

31、ecays to zero as the stored energy in windings is dissipatedSynchronous Machine-Sustained fault current- Affect of dampers and the field winding transients.Fault Current Contribution of MachinesRealistic Waveforms for Relay TestingType1Type2Type3TimedFaultLogicTimedFaultLogicTimedFaultLogicRRLRRLV1I

32、1TLine1TTLine2TTLine3TP+jQ75 km long second 230 kV transmission line 200 km long 230 kV transmission line simulated in twosegments to facilitate application of faults at different point on the line.Generate and record waveforms under different conditions batch mode simulation Different load conditio

33、ns (not included in the example case relay_test.psc) Point on wave Location Fault typeRealistic Waveforms for Relay TestingGenerate and record waveforms under different conditions batch mode simulation Multiple run component and other logic to control the simulations Waveforms recorded in COMTRADE f

34、ormat (or other)MultipleRunCh. 1V1V2V3V4Meas-Enab.TfRfTyp11I1LocLocType1LocType2LocType3*TypTypTyp0.010.5123I1I1I1StartEndAnalog Inputsv2.0 RTP RecorderNo.1File:playbackFormat:RTPComtrade 91Comtrade 99Digital InputsA1A2A3Other Examplesccvt_resonance.pscDiffRelay.psc (differential relay example)Some

35、other instances where EMT type simulations maybe necessary in relay studies Unbalanced operation of the system and the effect on relay settings (e.g. Unequal units in a three phase transformer bank, open conductor)Typical fault analysis programs are not able to handle such eventsHarmonics due to non

36、 linear loads and the effect on relaysIntegration of new technologyDistributed generationIslanding protectionComplex wind farm protection requirementsSome other instances where EMT type simulations maybe necessary in relay studies Investigate new relay conceptsE.g. Travelling wave relayComplexity du

37、e to parallel transmission lines on the same right-of-way (mutual coupling)Mechanical resonance issues (SSR)Bushings - transformer to SF6 gas duct3 bushings failed explosivelySome bushing removed for OverpressureDisagreements between groups within the company as to the cause. low oilThe power plant

38、is around 15 years old.Very Long Gas insulated bus-bars connect the GIS to the generator transformersEquipment Failure Analysis -Transformer Bushing failure In a power plant (if time permits) The Manitoba HVDC Research was contracted by an utility to perform apparatus inspections, and engineering st

39、udies (simulations) to investigate the causes for 380 kV transformer bushing failures at a power plant.The investigations concluded that the Very Fast Transients associated with Gas Insulated Substations most likely contributed to gradual deterioration of the bushing insulation.Equipment Failure Ana

40、lysis -Transformer Bushing failure In a power plant GIS Compact design Electrical properties of GIS equipment and bus bars are different to those of air insulated equipment Bus inductances and capacitances bushing capacitancesEquipment Failure Analysis -Transformer Bushing failure In a power plant S

41、witching transientsLightning induced transientsVOLTAGE PROFILE - INCOMING : Graphsx0.00 0.02m0.04m0.06m0.08m0.10m0.12m0.14m0.16m . . .-0.4k-0.2k0.0 0.2k0.4k0.6k0.8k1.0kV_9004Main : Graphsx0.000 0.050 0.100 0.150 0.200 . . .-2.00 -1.50 -1.00 -0.50 0.00 0.50 1.00 1.50 2.00 Voltage (pu)E_Open_line _end

42、Equipment Failure Analysis -Transformer Bushing failure In a power plant Section of a GIS Switching Station-4.0 -3.0 -2.0 -1.0 0.0 1.0 2.0 3.0 4.0 E_ST3_DER-1.00 -0.50 0.00 0.50 1.00 1.50 2.00 2.50 3.00 E_GT1_2GIS switching related VFT - MHz rangeEquipment Failure Analysis -Transformer Bushing failu

43、re In a power plant -4.0 -3.0 -2.0 -1.0 0.0 1.0 2.0 3.0 4.0 E_ST3_DERSlow operation of disconnect switches (DS) in (already de-energized segments of) a GIS can lead to multiple re-strikes as a result of re-distribution of trapped charges in stray capacitances. This will lead to travelling waves with

44、 very steep fronts. The travelling waves will get reflected at discontinuities and can result in very steep voltages of significant magnitude near equipment terminalsThis has the potential for insulation failure of equipment including transformers or minor internal faults in capacitively graded bush

45、ings 6Equipment Failure Analysis -Transformer Bushing failure In a power plant Equipment Failure Analysis -Transformer Bushing failure In a power plant IEEE , CIGRE provide guidelines on how to model different equipment of a GIS for a VFT investigationR=0(63)(63)MagPhdcF F TF = 100e3E_GT5_61300 Surg

46、e arrester (capacitance) to be addedTo 9002ToGT1/2- ST1ToGT 3/4ToGT7/8- ST2ToGT9/10- ST3ToGT 11/12a1b1b2a1b1b2a1b1b2a1b1b2a1b1b2a1b1b2a1b1b2a1b1b2a1b1b2a1b1b2a1b1b2a1b1b2a1b1b2a1b1b2ToGT 13/14ToGT15/16- ST4b1ab1b2ab1b2ab1b2ab1b2ab1b2K204K203K206ab1b2K606K603K604ab1b2K1006K1003K1004ab1b2K1806K1803K18

47、04ab1b2K2606K2603K2604ab1b2b13003002.6nF0.22uHE_GT5_6 Power Transformer300 pFToGT 5/612345665 88 m section76 44 m section 88 m section8 102.05 m section 23.8 m section96 88 m section1011 52.73 m section 19.67 m sectionSASA121313ST1GT 1/2GT 3/4SA141516SA17ST21819GT 7/8GT 5/619300 pF Power Transformer

48、E_GT7_82uH0.22.6nF2.6nF0.22uHE_ST2 Power Transformer300 pF300 pF Power TransformerE_ST12uH0.22.6nF300 pF Power TransformerE_GT3_42uH0.22.6nF300 pF Power TransformerE_GT1_22uH0.22.6nF2020 160.3 m section21 275.49 m section242425262728629303132 18.45 m section343333 18.45 m sectionST4SAGT 15/16SAGT 13/14SAGT