基于四开关三相变频器的永磁同步电机驱动系统转矩脉动优化控制

针对低成本三相四开关变频器构成的永磁同步电机驱动系统存在转矩脉动较大的问题,提出了一种系统转矩脉动优化控制策略。系统中存在的转矩脉动分为低频和高频转矩脉动,对于由直流电容电压波动产生的低频脉动,采用了引入一种基于非正交坐标变换的补偿方案,而对于高频脉动,分析评估了不同调制策略的影响,选择了最优调制策略。此外,线性调制范围设置考虑了系统直流电容电压波动,避免了低频脉动造成的过调制。同时,还设计了电容电压偏移抑制控制以扩大线性调制区范围。试验结果验证了新型控制策略抑制系统转矩脉动的效果明显。

Torque Ripple Optimal Control of PMSM Driving System Based onThree-Phase Four-Switch Inverter

The permanent magnet synchronous motor driving system based on three-phase four-switch inverter had the problem of the torque ripple. Aiming at it, a torque ripple optimal control of the system was proposed. The torque ripple in the system was divided into low frequency and high frequency torque ripple. The low frequency torque ripple was generated by the voltage fluctuation of the DC capacitor, and a compensation scheme based on nonorthogonal coordinate transformation had been introduced to compensate it. For the high frequency ripple, analysis and evaluation of effects of different modulation strategies, and the optimal modulation strategy had been chosen. In addition, the linear modulation range was taken into account, and the DC capacitor voltage fluctuation of the system was considered. At the same time, an adaptive capacitor voltage offset suppression method was designed to extended linear modulation range. The experimental results showed that the new control strategy could suppress the torque ripple.