弱磁用复合式转子永磁无刷直流电机设计

针对永磁无刷直流电机弱磁控制的要求,采用永磁段 磁阻段的复合式转子结构,实现基速以下恒转矩、基速以上恒功率的运行方式。理论上推导了永磁无刷直流电机弱磁的运行机理及电机模型,技术上针对交轴磁通路障式转子交、直轴磁路耦合严重、导磁材料非线性等特点,利用电磁场分析求解了交、直轴电枢反应电感,从而导出理论上弱磁运行的最高速。最后,对永磁无刷直流电机弱磁扩速范围对参数的依赖性进行了分析,归纳了弱磁控制用永磁无刷直流电机设计的特点。

Design of a PM Brushless D.C. Motor with Combined Rotor Structure Used for Flux Weakening

According to the demand of flux weakening control for a Permanent Magnet Brushless D. C. Motor (PMBLDCM) to achieve constant torque operation under the base-speed and constant power operation above the base-speed, the operation principle and mathematic model of the PMBLDCM with flux-weakening control were deduced in theory in this paper. Meanwhile, a kind of mixed rotor structure, which combined the PM section with a magnetic reluctance section together,was discussed in technic detail to compute the d- and q- axis armature reaction inductances and to predict the theoretical maximum speed under flux weakening operation. The influence of motor parameters on the speed region of flux weakening and design feature for this kind of motor were all investigated in the paper as well.