空间谐波对对称六相与三相PMSM串联系统的影响

摘要

The decouple operation of the series-connected symmetrical six-and three-phase permanent magnet synchronous motors (PMSMs) driven by single inverter is theoretically based on the sinusoid electromotive force.To study influences of space harmonics on the decouple control of the seriesconnected system,mathematic models for the series-connected system with the 2nd and 4th harmonics of a symmetrical six-phase PMSM are established in three different coordinates.The torque ripple expression of the six-phase PMSM induced by space harmonic is setup,which reveals mathematically the essence of harmonic effects on the decouple control of series-connected system.In addition,simulations are conducted for two PMSMs with variable speed and variable loads.The results show that the torque ripple changes are caused by the 2th and 4th space harmonics of the symmetrical six-phase PMSM;consequently,operations of the series-connected two PMSMs cannot be controlled independently and need a corresponding compensating control.%单逆变器驱动的对称六相永磁同步电机(PMSM)串联三相PMSM解耦运行的理论基础是电机的反电动势必须为正弦波分布.为了研究电机中的非正弦空间谐波对串联系统解耦控制的影响规律,分别建立了对称六相PMSM含有2次和4次空间谐波的串联系统在3种不同坐标系下的数学模型,推导了非正弦空间谐波引起的六相PMSM电磁转矩脉动表达式,揭示了空间谐波对串联系统解耦运行影响的本质,并对两台电机变速、变负载等不同工况进行了仿真研究.结果表明,对称六相PMSM的2次和4次空间谐波导致其电磁转矩的脉动变化,无法实现对称六相串联三相PMSM系统的独立控制,需要进行相应的补偿控制.