An Improved Nonzero Vector Based Common-Mode Voltage Suppression Strategy for Permanent Magnet Synchronous Motors

In order to suppress the negative influence of common mode voltage (CMV) in the permanent magnet synchronous motor (PMSM) control system, a feasible modulation method in the system, the improved AZSPWM3-4 algorithm, is proposed by analyzing and comparing the advantages and disadvantages of the existing non-zero vector pulse width modulation (NZPWM) strategy. In one control cycle, V3 is used to synthesize the reference vector, avoiding the employment of the zero vector, thus reducing the common mode voltage (CMV). In comparison with the traditional space vector pulse width modulation (SVPWM), the algorithm has the same modulation range and great dynamic and stable performance in the permanent magnet synchronous motor control system. In addition, it can reduce the amplitude of common mode voltage (CMV) from Udc/2 to Udc/6. The feasibility and stability of this method have been proved by comparing with existing modulation methods and the experimental results.