PWM调制对无刷直流电机转子涡流损耗的影响  

Influence of PWM on Rotor Eddy-Current Losses in Brushless DC Motor

作　　者：解恩[1] 刘卫国[1] 罗玲[1] 王璞[1] 

机构地区：[1]西北工业大学自动化学院,西安710072

出　　处：《电工技术学报》2013年第2期117-125,共9页Transactions of China Electrotechnical Society

基　　金：国家自然科学基金资助项目(90716026)

摘　　要：针对无刷直流电机在PWM调制下转子涡流损耗问题,由于在空间上,运动的转子切割电枢磁场会感应出电动势;在时间上,PWM引起的电枢磁动势变化及电机齿槽磁通密度变化也会在转子上感应出电动势,所以文中将这3种转子上感应电动势分别定义为运动电动势、感应电动势和齿槽电动势。在不考虑涡流反应的前提下,对11kW无刷直流电机在典型工作点选择最大曲面和最大闭合曲线分别计算运动电动势和感应电动势并分析,得到时间感应电动势远大于空间运动电动势(齿槽电动势未计),并且得到PWM占空比等于50%时,时间感应电动势达到最大。通过设计多组电机对拖加载温升实验,分离出三种涡流电动势对应的转子温升,实验结果验证了所提出的观点。The eddy-current losses in the rotor of brushless DC motor （BLDCM） under PWM modulation can mainly be divided into three parts. In terms of space, moving rotor cuts armature magnetic field, and electromotive force （EMF） is induced. In terms of time, variation of both armature magnetic potential caused by PWM and cogging flux density can induce EMF. In this paper, these three parts of EMF are defined as motional EMF, induced EMF and cogging EMF, respectively. Without considering eddy reaction, motional EMF and induced EMF of an llkW BLDCM are calculated and analyzed by selecting maximum curved surface and closed curve at typical operating point. It can be found that the induced EMF is higher than motional EMF （cogging EMF is not considered）, and the induced EMF is maximum when duty cycle equals to 50%. The rotor temperature rise caused by above three kinds of EMF is obtained respectively by pair-drive loading experiment. The experimental results verify the proposed method very well.

关 键 词：无刷直流电机 转子涡流损耗 运动电动势 感应电动势 齿槽电动势 对拖实验转子温升 

分 类 号：TM351[电气工程—电机]