与传统的三相星形绕组永磁同步发电机(PMSG)PWM整流系统相比,双PWM整流器控制的开绕组PMSG系统具有容错性高,拓扑结构灵活等特点。但当双整流器共用一个直流母线时,产生了一个零序电流通路,因此在采用空间电压矢量(SVPWM)控制时算法中存在的零序电压分量就会在通路中产生零序电流。对于永磁电机而言,电机反电势中的三次谐波分量也会产生一个相应的零序电流。因此,为了最大程度地减小电机绕组内的零序电流,本文提出采用零序电流调节器,可使电机相电流波形趋近正弦,整流后得到的直流母线电压稳定且纹波小。仿真和实验结果验证了该系统的有效性。
Compared with the traditional Y-connected winding permanent magnet synchronous generator (PMSG) PWM rectification system, the dual-rectifier controlled open-winding PMSG system has the advantages of higher fault tolerance and more flexible topology. When the dual-rectifier uses a common DC bus, a zero-sequence current path is formed. When the dual-rectifier system uses the space vector pulse width modulation (SVPWM) control, the algorithm can produce a zero-sequence voltage which leads to the zero-sequence current in the path. The third harmonic back EMF that may exist in the PMSG will also produce a corresponding zero-sequence current. In order to suppress the zero-sequence current in the stator wingdings, a zero-sequence current regulator was proposed in this paper, which made the phase current more sinusoidal, and stabilized the rectified DC bus voltage with less ripple. Both simulation and experimental results validate the effectiveness of the proposed system.