PWM供电时高速永磁电机的谐波特征及损耗研究

Study of Eddy Current Losses of High Speed Permanent Magnet Machine when Applied by PWM Source

转子温升是高速永磁电机温升控制的重点,考虑脉宽调制(Pulse Width Modulation,简称PWM)供电对转子涡流损耗的影响尤为重要。本文分析了PWM供电时主要谐波的产生机理,结合具体设计案例,针对表面式高速永磁电机(SPM)转子结构开展了方案设计,搭建了基于场路耦合的有限元仿真分析模型,并通过仿真分析,总结了PWM供电时电压、电流各谐波分量的幅值、相位变化规律,并对比分析了不同供电质量时的转子涡流损耗。仿真结果揭示了PWM供电时各谐波分量的组成及变化规律,同时表明,谐波分量使得转子的涡流损耗显著增加,设计时必须予以考虑。本文的结论可为高速永磁电机的设计及转子涡流损耗的分析提供一定的参考依据。

The temperature rise of rotor of High Speed Permanent Magnetic Machine(HSPMM)is the key point to be controlled,so it is important to consider the effect of a Pulse Width Modulation(PWM)fed on eddy current losses.This paper analyzes the mechanism of production of main harmonics when supplied by a PWM sources,and also presents the scheme of a specific design case in Surface Permanent Machine(SPM)structure.The field-circuit coupling models are built,by which the characteristic of harmonic components in voltage and current are calculated and summarized,as well as the eddy current losses under different supply condition.The results reveal the harmonic components of applied voltage and current when PWM source is applied,and shows that the eddy current loss will increase obviously.The conclusions could supply some beneficial reference for design and loss calculation of HSPMM.