逆变器-永磁无刷电动机系统数学模型与仿真

Mathematical Model and Simulation of Inverter-Permanent Magnet Brushless Motor System

永磁无刷电动机以其功率密度高、调速范围宽以及运行效率高而广泛应用于电动车辆的驱动系统,而采用120°方波电流控制的永磁无刷电动机虽然控制方式简单,但仿真分析模型复杂。寻求一种简洁实用的仿真模型对于分析永磁无刷电动机的转矩脉动、提升控制性能十分关键。本文引入电压开关函数建立了永磁无刷电动机仿真与分析模型,该模型综合考虑逆变器开关过程、电感续流过程、电动机换流过程中的动态电流变化过程。仿真和实验结果比较验证,该仿真模型能够近似描述永磁无刷电动机实际工作过程,可应用于分析永磁无刷电动机转矩脉动以及弱磁控制性能等,提高实际调试效率。

Permanent magnet brushless motor（PMBM） is widely used in driving system of electric vehicle because of its high power density, wide speed regulation and high efficiency. 120° square current for PMBM is simple in control method, but complex in simulation. A kind of simple and useful model for PMBM is the key point for analyzing the torque ripple and upgrading its performance. This paper presents a model of PMBM based on the voltage switch function which covers the dynamic change such as the switching course of the inverter, the current of induction continuation, and the current changing procession. According to the comparison to the simulation result and the experimental result, the model can describe the working proces of the motor. The motor model is useful to analyze the torque ripple and controlling performance of the PM motor, and efficiency of debug PMBM system will be enhanced.