Analytical Study of Influence of Carrier Frequency of Inverter on Rotating Performance of Permanent Magnet Synchronous Motor

摘要

This paper presents analytical study results for the relationship between carrier frequency of inverter and performance of permanent magnet synchronous motor (PMSM), of which mechanical output is 60 kW. Compared with traditional methods, the proposed method can improve the total efficiency, comprehensively considering the inverter's losses and motor's loss. The analysis is carried out based on voltage equations and an equation of torque. And the inverter's losses which include the conducting loss and switching loss are considered for estimating the total power dissipation. The relationship among carrier frequency, total harmonic distortion of current and torque is also analyzed. The optimal carrier frequency can be clarified according to the total loss of inverter and motor, the average torque, and the total harmonic distortion. Thus, it can increase the total efficiency of the system which includes inverter and motor. Different optimal carrier frequencies of inverter at different rotating speed of motor can be chosen, providing reference for minimizing losses of system in motor's whole speed region.