9.两电平牵引逆变器的工作原理

牵引逆变器可分为:电压源型和电流源型.为同步电机供电的大多采用电流源型逆变器，例如：韩国KTX高速列车。为异步电机供电的大多采用电压源型逆变器，例如：我国现有电力机车和高速列车全部采用电压源型逆变器。根据输出电平数的不同，电压源型牵引逆变器又可分为两电平和三电平两种。例如：CRH2、CRH380A高速列车为三电平拓扑HXD系列电力机车和CRH1、CRH3、CRH5为两电平拓扑2电路有23=8个开关状态，对应着八种工作模式。Uab的取值有Udc、0和-Udc三种电平。aTapTcnTbpTanbcTcpTbnUdcidcM3~iaibicabcUdcidciaibic01SbSa10Sc10ZaZcZbNapanaapan1Ton,Toff0Toff,TonSbpbnbbpbn1Ton,Toff0Toff,TonScpcnccpcn1Ton,Toff0Toff,TonS3-ZaZbZcNabcUdcidciaibic01SbSa10Sc10ZaZcZbN开关Tan,Tbn和Tcn导通，Tap,Tbp和Tcp关断。uaN=ubN=ucN=0;uab=ubc=uac=0。工作模式0(SaSbSc=000)：aTapTcnTbpTanbcTcpTbnUdcidcM3~iaibic45+-ZcZaZbNabcUdcidciaibic01SbSa10Sc10ZaZcZbN开关Tan,Tbn和Tcp导通，Tap,Tbp和Tcn关断。uaN=ubN=-Udc/3,ucN=2Udc/3;uab=0,ubc=uac=-Udc。工作模式1(SaSbSc=001)：aTapTcnTbpTanbcTcpTbnUdcidcM3~iaibic6+-ZcZbZaNabcUdcidciaibic01SbSa10Sc10ZaZcZbN开关Tan,Tbp和Tcn导通，Tap,Tbn和Tcp关断。uaN=ucN=-Udc/3,ubN=2Udc/3;uab=ucb=-Udc,uac=0。工作模式2(SaSbSc=010)：aTapTcnTbpTanbcTcpTbnUdcidcM3~iaibic7+-ZaZbZcNabcUdcidciaibic01SbSa10Sc10ZaZcZbN开关Tap,Tbp和Tcn导通，Tan,Tbn和Tcp关断，uaN=-2Udc/3,ubN=ucN=Udc/3;uab=uac=-Udc,ubc=0。工作模式3(SaSbSc=011)：aTapTcnTbpTanbcTcpTbnUdcidcM3~iaibic8+-ZcZbZaNabcUdcidciaibic01SbSa10Sc10ZaZcZbN开关Tap,Tbn和Tcn导通，Tan,Tbp和Tcp关断，uaN=2Udc/3,ubN=ucN=-Udc/3;uab=uac=Udc,ubc=0。工作模式4(SaSbSc=100)：aTapTcnTbpTanbcTcpTbnUdcidcM3~iaibic9Zc+-ZbZaNabcUdcidciaibic01SbSa10Sc10ZaZcZbN开关Tap,Tbn和Tcp导通，Tan,Tbp和Tcn关断。uaN=ucN=Udc/3,ubN=-2Udc/3;uab=ucb=Udc,uac=0。工作模式5(SaSbSc=101)：aTapTcnTbpTanbcTcpTbnUdcidcM3~iaibic10abcUdcidciaibic01SbSa10Sc10ZaZcZbNaTapTcnTbpTanbcTcpTbnUdcidcM3~iaibic开关Tap,Tbp和Tcn导通，Tan,Tbn和Tcp关断。uaN=ubN=Udc/3,ucN=-2Udc/3;uab=0,ubc=uac=Udc。+-ZaZbZcN工作模式6(SaSbSc=110)：11aTapTcnTbpTanbcTcpTbnUdcidcM3~iaibicabcUdcidciaibic01SbSa10Sc10ZaZcZbN工作模式7(SaSbSc=111)：开关Tap,Tbp和Tcp导通，Tan,Tbn和Tcn关断。uaN=ubN=ucN=Udc,uab=ubc=uca=0。+ZaZbZcN12SaSbSc000001101111110ModeuabubcucaucNubNuaN000000-Udc/301234567-Udc/32Udc/3-Udc/32Udc/3-Udc/3-2Udc/32Udc/3Udc/3Udc/30Udc/3-2Udc/3-Udc/3Udc/3Udc/3-Udc/3Udc/3-2Udc/30-UdcUdc00000-UdcUdc0-Udc0UdcUdc0-UdcUdc-Udc00Udc-UdcVector010011100V5V0V1V4V3V7V6V2逆变器的开关状态表()(,,,)ijijdcuSSUijabc(2)3abcaNdcSSSuU(2)3aacbNdcSSSuU(2)3cabcNdcSSSuU相电压：2Udc/3,Udc/3,0，-Udc/3,-2Udc/3一共5种电平线电压：Udc,0,-Udc一共3种电平两电平逆变器的脉宽调制正弦脉宽调制SPWM空间矢量脉宽调制SVPWM(应用最为广泛)两电平逆变器SPWM示意图相电压与线电压的仿真与实验波形t(10ms/格)uAB(1000V/格)iAB(200A/格)uABiA1212.0512.112.1512.2-3000-2000-10000100020003000t/s电机相电压/VuAB(1000V/格)iAB(200A/格)t(10ms/格)uABiA1919.00519.0119.01519.0219.02519.03-3000-2000-10000100020003000t/s电机相电压/V相电压仿真波形相电压仿真波形线电压与电机定子电流的半实物实验波形线电压与电机定子电流的半实物实验波形