简介:一、相位飘移问题无论单极旋转变压器还是多极旋转变化器,在长期通电过程中,都会产生相位飘移。所谓相位飘移,就是电机激磁绕组通电发热后,会引起输人阻抗发生变化,从而使输出电压相位发生变化,这就是相位飘移。相位飘移对于单极机并不重要,因单极机精度要求低,且零位误差只测四点,测试速度快,造成的影响可以忽略不计。对于多极机就不一样了。多极机由于零位误差的测点很多,测试时间一般拉得很长,相位飘移很显著,由相位飘移引起的零点多达数秒,往往很快摇一周能够回零的电机,测试完一周零位误差后,就不能再回零了。这种飘移,显然不能达到高精度的多极机测试的要求。下面是笔者对某30对极多极旋变作的相位飘移对零
简介:针对汽车电动助力转向系统的无刷直流电机转子位置检测的问题,介绍了一种新型的磁阻式正余弦旋转变压器解码方法。该方法使用新型旋变数字转换器AD2S1210对旋变输出信号进行解码,并设计了芯片外围电路、激励信号缓冲电路和数字接口电路。解调后的信号通过串行输出模式输出,将角位置信息送入单片机dsPIC30F6010,转子位置信息的读取采用单片机内部的EEPROM存储器数据表调用方式,最后得到类似于3个霍尔元件检测产生的互差120°的方波信号,实现了旋变模拟量到数字量的转换。所设计方案用于汽车电动助力转向系统的无刷直流电机转子位置检测,验证了该方法的可行性。
简介:Capabilitiesofgas-analyticaltransformerdiagnosticstoclearupfailures,CapacitychangeofsolidinsulatorsundertheinfluenceofAChighvoltage,Chargeaccumulationcausedbystreamingelectrificationintransformeroil,Comparisonofdifferentneuralnetworksalgorithmsusedinthediagnosisandthermalageingpredictionoftransformeroil,ConductionofWaterClustersinModifiedAgedOil,DechlorinationofPolychlorinatedBiphenylsinIndustrialTransformerOilbyRadiolyticandPhotolyticMethods。
简介:Anumericalapproachtotheevaluationofuncertaintyinnonconventionalmeasurementsonpowersystems,Asimplemethodforcalculatingwindingtemperaturegradientinpowertransformers,Ageingandlife-managementofpowertransformers,Aninvestigationintotheinternalovervoltagesgeneratedbydisconnectorsingasinsulatedsubstations
简介:ApplicationofZig-ZagTransformersinaThree-wireThree-phaseDynamicSagCorrectorSystem,ApplyingTransformerConcepttoNon-isolatedVoltageRegulatorsSignificantlyImprovestheEfficiencyandTransientResponse,BDVRTECHNOLOGY-AMULTIFUNCTIONRIDE-THROUGHSYSTEMFORADJUSTABLESPEEDDRIVESOFCRITICALLOADS,Bi-directionalsingle-phasehalf-bridgerectifierforpowerqualitycompensation,ChoiceofUtilityFunctionsforAdaptiveCriticDesigns,CompactDSPApplicationforalOOkWDCPowerSupply,ComparisonaboutFiveCandidatesfor12VVRMTopology。
简介:ADC/ACconverterforsingle-phasegrid-connectedphotovoltaicsystems-IECON'02;ANEWZVTDC-TO-DCFULLBRIDGECONVERTER;AThree-PhaseAC/ACHigh-FrequencyLinkMatrixConverterforVSCFApplications;Analysisofeffectiveresistanceandeddy-currentlossesinmultiturnwindingofhigh-frequencymagneticcomponents;Bi-polarityphase-shiftedcontrolledvoltagemodeAC/ACconverterswithhighfrequencyaelink;Contactlesspowerandinformationtransmission;
简介:1ATMSUBCOOLEDLIQUIDNITROGENCRYOGENICSYSTEMWITHGM-REFRIGERATORFORAHTSPOWERTRANSFORMER;Acontactlesselectricalenergytransmissionsystemforportable-telephonebatterychargers;Acurrent-basedsolutionfortransformerdifferentialprotection-PartⅡ:relaydescriptionandevaluation;Aforwardconvertertopologyemployingaresonantauxiliarycircuittoachievesoftswitchingandpowertransformerresetting;Anewmethodbasedonwaveletpackettransformationtoreducenarrowbandnoiseinon-sitePDmeasurement;ANewMethodfortheCalculationoftheHot-SpotTemperatureinPowerTransformersWithONANCooling;