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7.2、电气试验ElectricTest1.电气试验常规要求GeneralRequirements1)电气预防性的试验严格按规范、产品说明书要求执行。Electricpreventivetestshallbecarriedoutinaccordancewithcriterionandproductspecificationstrictly.2)组合式微机保护及监控继电器按产品说明书进行整定。Adjustcombinedmicro-computerprotectionandmonitoringrelay3)常规的电磁式继电器调试按《新编保护继电器检验》中有关规定进行调试。ThenormalelectromagneticrelaycommissioningshallcomplywiththestipulationsofNewProtectionRelayTest.4)盘(柜)指示电表经校验后,对合格的电表粘贴专用合格证。Aftercalibrationofthepanel(cabinet)indicativeammeter,pastespecialqualitycertificateonthequalifiedammeter.5)高压开关柜的传动试验在各电气元件及单体柜调试后进行。传动试验时,认真核对各回路的准确及可靠性。主要传动试验项目:Highpressureswitchboardtransmissiontestshallbecarriedoutafterelectricalelementandindividualcabinetcommissioning.Checktheloopsaccuracyandliabilityduringtransmissiontest.Themaintransmissionproject:操作控制回路传动试验;OperationControlLoopTransmissionTest保护回路传动试验;LoopProtectionTransmissionTest测量/计量回路试验;Measure/RecordingLoopTest系统低电压、断线保护试验;SystemLowPressure,Cablebreakprotectiontest核对一、二次相位;Check1stand2ndphase2.变压器试验TransformerTest1)测量绕组连同套管的直流电阻,测量应在各分接头所有位置上进行;MeasurewindingandsleeveDCresistanceofalltheconnectionjoints.2)对1600kVA及以下三相变压器,各相测得值的相互差值应小于平均值的4%,线间测得值的相互差值应小于平均值的2%;1600kVA以上的三相变压器,各相测得值的相互差值应小于平均值的2%,线间测得值的相互差值应小于平均值的1%;1600kVA以上的三相变压器,各相测得值的相互差值应小于平均值的2%,线间测得值的相互差值应小于平均值的1%;(重复)三相电阻不平衡率计算ThreePhaseTransformerof1600Kvaandtheless,themeasuredvalue’sdifferenceshallbe4%lessthantheaverage,internallinesmeasuredvalueshallbe2%lessthantheaverage.ThreePhaseTransformerofabove1600kVA,themeasuredvalue’sdifferenceshallbe2%lessthantheaverage,internallinesmeasuredvalueshallbe1%lessthantheaverage,ThreePhaseresistanceUnbalanceRatecalculationformula:MeasuredMax-MinUnbalancedRate=100%Average3)直阻测量方法:DCResistanceMeasureMethod用感性负载速测欧姆计测量绕组直流电阻时,其接线及测量方法应符合测试仪器的技术要求。WhenmeasuringwindingDCresistancebysensibilityloadohmmeter,theconnectionandthemeasuremethodshallcomplywithequipmenttechnicalrequirements.4)变压器的直流电阻,与同温下产品出厂实测数值比较,相应变化不应大于2%;将不同温度下的绕组直流电阻温度换算到同一温度:DCresistanceoftransformer,comparedwithmeasuredvalueofproductbymanufacturerundersametemperature,thecorrespondingchangeshallbenotmorethan2%,convertthewindingDCresistanceunderdifferenttemperatureintothesametemperature.axaXtTtTRR%100三相算术平均值最小值三相实测最大值不平衡率(式中:Rx–换算至温度为tx时的电阻;Ra-温度为ta时所测得的电阻;T-温度换算系数,铜线为235,铝线为225;tx-需要换算Rx的温度;ta-测量Ra时的温度)(convertRxintotheresistanceundertemperatureoftx,Raisresistanceundertemperatureofta,Tistemperatureconvertcoefficient,copperlineis235,aluminumis225,txisthetemperatureofRxtoconvert,taistemperatureofmeasuringRa)5)由于变压器结构等原因,差值超过本条第⑵款时,可只按本条第⑷款进行比较。Causeoftransformerstructure,thedifferenceismorethanclause2,complywithclause4only.6)检查所有分接头的变压比变压比与制造厂名牌数据相比应无明显差别,且符合变比的规律。额定分接的变压比允许偏差为±0.5%,其它分接的偏差应在变压器阻抗值(%)的1/10以内,但不超过1%。Checkallconnectionjointstransformingratio,whichshallbenodistinctdifferencecomparedwiththedateofmanufacturerbrandandcomplywiththetransformingrule.Ratedtaptransformingratioallowabledifferenceis±0.5%,othersshallwithin1/10oftransformerresistance(%),butnotmorethan1%.7)检查三相变压器的结线组别和单相变压器引出线的极性Checkthreephasetransformerwireseriesandpolarityofsinglephasetransformeroutputwire.8)测量绕组连同套管的绝缘电阻Measuretheinsulationresistanceofwindingandsleeve.a)绝缘电阻值不应低于出厂试验值的70%。Insulationresistanceshallbenotlessthan70%ofleavefactorytestingvalue.b)当测量温度与产品出厂试验时温度不符合时,可按下表换算到同一温度时的数值进行比较:Ifanyunconformitybetweenmeasuredtemperatureandleavingfactorytestingtemperature,convertintosametemperatureaccordingbelowtableandcompare:温度差TemperatureDifferenceK51015202530354045505560换算系数ConvertingCoefficientA1.21.51.82.32.83.44.15.16.27.59.211.2(注:表中K为实测温度减去20℃的绝对值)(Remark:Kistheabsolutevalueofmeasuredtemperatureminus20℃)c)当测量绝缘电阻的温度差不是表中所列数值时,其换算系数按下列公式计算:whentemperaturedifferenceofmeasuringinsulationresistancevaluecannotbefoundintheabovetable,theconvertingformulais:A=1.5K/10当实测温度为20℃以上时:Whenmeasuredtemperatureisabove20℃R20=ARt当实测温度为20℃以下时:Whenmeasuredtemperatureisbelow20℃R20=Rt/A(式中:R20-校正到20℃时的绝缘电阻值;Rt-在测量温度下的绝缘电阻值)(R20-revisetoabsolutevalueof20℃,Rt-istheabsoluteresistancevaleundermeasuringtemperature)9)交流耐压试验ACWithstandVoltageTest根据制造厂提供的技术资料及业主的要求决定是否进行该项试验;如进行该项试验需制造厂提供试验电压值。InaccordancewiththetechnicaldocumentsprovidedbymanufacturerandClient’srequirementstodeterminewhethertocarryoutthetest,ifdoit,themanufactureshouldprovidetestvoltagevalue.a)试验电压的频率为50Hz,电压波形应尽可能接近正弦波形。Thetestingvoltagefrequencyis50Hz,voltagewaveformbetterbesinewave.b)进行交流耐压时,非被试侧绕组应短接后接地。CarryoutACwithstandvoltagetest,theun-testsideofthewindingresistanceshouldbeearthed.10)测量与铁芯绝缘的各紧固件的绝缘电阻measuretheresistanceofironcoreinsulationfasteningwarea)应测量可接触到的穿芯螺栓、轭铁夹件及绑扎钢带对铁轭、铁芯及绕组压环的绝缘电阻;Measurethetouchablepenetrationbolt,yokeclamp,steelbandingyoke,steelcoreandwindingringinsulationresistance.b)采用2500V兆欧表测量,持续时间为1分钟,应无闪络及击穿现象;measuringwith2500ohmmeter,tinelast1minute,noflashover,nobreakdown.c)当轭铁梁及穿芯螺栓一端与铁芯相连时,应将连接片断开后进行试验;Whenonesideofyokebeamsandpenetrationboltsconnectedwiththecore,carryoutTestafterdisconnectingtheclips.11)冲击合闸试验ImpactClosingTest在额定电压下对变压器进行冲击合闸试验,应进行5次,每次间隔宜为5分钟,无异常现象。冲击合闸试验宜在变压器高压侧进行;对中性点接地的电力系统,冲击试验时变压器的中性点必须接
本文标题:电气试验-7
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