Performance evaluation of adjustable space-vector PWM strategy for open-winding PMSM drives

The performance evaluation of an adjustable space-vector (SV) PWM (SVPWM) strategy for open-winding (OW) permanent magnet synchronous machine (PMSM) (OW-PMSM) drives with common DC bus is presented. Different from modifying the conventional SVPWM algorithm, the proposed method is realized by reconstructing the voltage references for individual SVPWM module. No need of modification on a conventional SVPWM means that it can be easily implemented on the OW voltage source inverter based drive systems. It can be easily adjusted to generate matching common mode voltage (CMV) to compensate other zero sequence disturbances including zero sequence back EMF, zero sequence cross coupling voltages and inverter nonlinearities within OW-PMSM drive and consequently to achieve zero sequence current suppression capability. In the experimental evaluation, for the tested 3kW OW-PMSM containing 13% zero sequence back EMF, the proposed method typically achieves 8.51% higher DC bus voltage utilization and reduces 58.9% of the peak-to-peak value of the zero sequence circulating current when compared to the conventional phase shift based method.