基于绕组分布函数理论和动态磁网络的两种内置式永磁牵引电机解析建模方法

Two Analytical Models Based on Winding Function Theory and Dynamic Reluctance Mesh for Interior Permanent Magnet Traction Machines

在高速列车中压大功率应用场合中,较低的开关频率迫使脉冲宽度调制(PWM)变流器采用低载波比的同步调制方式,使得永磁牵引电机的谐波损耗激增,正弦激励下的电机特性仿真分析已无法满足电机全局优化设计需求。高性能永磁牵引电机的设计不仅需要考虑电机结构产生的空间谐波,还需考虑PWM激励带来的时间谐波。有限元分析方法需要大量的计算资源,无法满足快速、准确的优化设计需求。针对此问题,该文分别基于绕组分布函数理论和动态磁网络方法建立两种内置式永磁牵引电机解析模型,对电机空载、正弦与PWM激励额定工况下的电磁特性进行分析,通过有限元分析与实验验证并分析对比两种解析模型的准确性,为PWM激励下永磁牵引电机解析计算提供理论指导。

In the medium-voltage and high-power applications of high-speed trains,low carrier ration synchronous modulation for pulse width modulation(PWM)inverters with low switching frequency results in a dramatic increasement of harmonic losses in permanent magnet traction machines(PMTM).Thus,the simulation of machine performances under sinusoidal excitations can no longer fulfill the requirements of high-performance PMTM overall optimal designs,which must consider the space harmonics from the machine structure as well as the time harmonics from the PWM excitations.Due to its requirement of massive computing resources,the finite element analysis(FEA)can barely meet the needs of rapid and accurate optimal designs.In order to solve these problems,this paper builds two analytical models for interior PMTM based on the winding function theory and the dynamic reluctance mesh.The electro-magnetic performances are analyzed using the analytical models under the no-load operation along with the rated operation with sinusoidal and PWM excitations.The simulation results are verified by the FEA and the experimental tests,and the features of both models are discussed.The conclusions provide theoretical guidance for the analytical calculation of PM traction machines under PWM excitations.