一种五相异步电动机直接转矩控制策略

A Strategy for Direct Torque Controlled Five-Phase Motor

针对三相异步电动机直接转矩控制(DTC)因转矩脉动大而影响调速性能的不足,采用五相电动机来代替三相电动机。推导了五相逆变器电压空间矢量的表达式,分析了其对五相电机定子磁链作用的规律,并以此对电压矢量进行分级,建立了五相电机DTC的开关状态表。针对该表的不足,提出了一种改进方法,该方法具有方便、快速的特点,仿真验证了该方法的正确性。通过与三相异步电动机DTC的对比,证明了该方法应用于五相异步电动机能改善电机的转矩脉动,取得较好的控制效果。

To avoid disadvantages of large torque ripple and bad speed regulation, five-phase asynchronous machine is adopted to avoid those disadvantages. The expressions of voltage space vector of five-phase inverter is deduced, and the effect put on stator flux linkage is analysed. Voltage space vector is classified to form the switching table for Direct Torque Control（DTC） of the five-phase motor. For switching table is huge, an improved strategy is proposed, which is more convenient and faster than conventional methods. The validity of the method is verified by simulation. Through the comparison of torque performance between three-phase and five-phase DTC method, it is proved that when applying to five-phase asynchronous motor, this improved DTC strategy proposed can reduce the torque ripple, achieve good control performance.