关键词: 永磁同步电机, 脉宽调制, 电流分析, 谐波损耗, 损耗分析

Abstract: With the development of new energy vehicle and high-efficiency motor technologies, aiming at the loss problem of vehicle permanent magnet synchronous motor ( PMSM) powered by pulse-width modulation( PWM) inverters,a 6-layer flat wire interior PMSM was taken as the research object to investigate the quantitative effects of switching frequency,DC bus voltage and rotational speed on the harmonic current and losses of the motor by combining theoretical analysis,simulation and experimental measurement. The results show that the total harmonic distortion ( THD) of the current decreases from 11. 47% to 7. 40% when the switching frequency varies from 8 kHz to 14 kHz, and the THD presents an increasing trend as the DC bus voltage rises from 500 V to 700 V. In comparison with sinusoidal drive, the iron loss and copper loss under PWM drive increase by 1. 3 times and 1. 2 times respectively, while the eddy current loss of the permanent magnet rises by tens to hundreds of times, with the motor losses showing a positive correlation with the THD. Comprehensive consideration of the three aforementioned factors in engineering applications can maximize the operational efficiency of the PMSM system.

Key words: permanent magnet synchronous motor, pulse-width modulation, current analysis, harmonic loss, loss analysis