采用三通道法测量变压器直流电阻时应注意的问题

5283OOTM406B1001-8425200606-0034-03!YN2.112O'2ABCIAIBICI'N=IB-ICIN=IA-I'N=IA+IC-IBRAO=U1IA=IARA+RXO'+INROO'IA=RA+RXO'+INIAROO'RBO=U2IB=IBRB+I'NRYO'-INROO'IA=RB+IB-ICIBRYO'-INIAROO'=RB+RYO'-ICIBRYO'-INIBROO'RCO=U3ICICRC+RYZ-I'NRYO'+INROO'IC=RC+RYZ-IB-ICICRYO'+INICROO'=RC+RYZ+RYO'-IBICRYO'+INICROO'1/2/1A5/10/5AIA=IC=12IBIN=0RAO=RA+RXO'1Fig.1Connectiondiagraminmeasurementofmaintransformerresistanceofthreecircuitsconstant-currentsource2Fig.2Testprinciplediagramofmaintransformerresistanceofthreecircuitsconstant-currentsource!#$%%##TRANSFORMER&’()!*+,-.’)#$%%#6RBO=RB+12RYO'RCO=RC+RYZ-RYO'12.23454ABCIAIBICIN=0RAO=UA-UOIA=IARA+IARXO'IA=RA+RXO'RBO=UB-UOIB=IBRB+IARYO'IB=RB+IAIBRYO'RCO=UC-UOIC=ICRC+ICRYZ-IARYO'IC=RC+RYZ-IAICRYO'IA≈IC=12IBRAO=RA+RXO'RBO=RB+12RYO'RCO=RC+RYZ-RYO'25IA=IC42.312RAO=RA+RXO'+ROO'RBO=RB+RYO'+ROO'RCO=RC+RYZ+RYO'+ROO'2.412313O'O'!3.1121212.7mΩ～3.4mΩ1%3Fig.3Connectiondiagraminmeasurementofmaintransformerresistanceofoneandtwocircuitsconstant-currentsource4Fig.4Testprinciplediagramofmaintransformerrestistanceofonecircuitconstant-currentsource5Fig.5Testprinciplediagramofmaintransformerresistanceoftwocircuitsconstant-currentsource1250000kVA/110kV110kV/Ω/Ω1212AO0.33310.32790.33000.3245BO0.33440.32880.33130.3254CO0.33490.32980.33220.3265ΔR/%0.540.580.660.61Table1DCresistanceinAnrenstreetNo.250000kVA/110kV(110side)maintransformer354325-7-151957-ProblemstoMeasureTransformerDCResistancewithThreeChannelMethodDINGWeiNanjingPowerSupplyCompany,Nanjing528300,ChinaAbstractTheprincipletomeasuretransformerDCresistancewiththreechanneltesterisana-lyzed.Itsconnectionintestisanalyzedanddiscussed.Theproblemsanderrorsintestarepre-sented.KeywordsTransformerDCresistanceMeasurement1rror2281µΩ～545µΩ2.9%～5.37%3.233!12322125000kVA/220kV35kV/Ω/ΩaO0.010140.009595bO0.0099320.009563cO0.0096940.009413ΔR/%4.501.91Table2DCresistanceinYaohuamenNo.2125000kVA/220kV(35kV)maintransformer3500kVA/10kV400VTable3DCresistanceof500kVA/10kV(400Vside)transformer/Ω/ΩaO0.0010980.0009510.0014430.000950bO0.0010800.0009250.0014250.000926cO0.011100.0009520.0014540.000952!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!#$%&&&’()*’(*+36