基于固定矢量作用时间的新型直接转矩控制系统

A Novel Direct Torque Control System Based on Fixed Action Time of Vectors

永磁同步电动机传统直接转矩控制具有转矩脉动大、开关频率不恒定等缺点,在分析传统直接转矩控制中磁链和转矩脉动的基础上,利用固定矢量作用时间合成新矢量的新型直接转矩控制方法控制永磁同步电动机。该方法根据转矩和磁链误差来选择基本电压矢量对,根据磁链的位置和转矩误差的大小来确定所选择的基本电压矢量的作用时间,从而得到了新的合成电压矢量进行控制。仿真结果表明基于固定矢量作用时间的新型直接转矩控制方法能够有效减小传统直接转矩控制方法中的磁链和转矩脉动,同时不增加控制的复杂性,明显改善了系统的控制性能。

Traditional direct torque control （ DTC ） method of permanent magnet synchronous motors （PMSMs） has disadvantages of high torque ripples and inconstant switching frequency. A novel DTC method of PMSMs using fixed vector time pairs to compound new vectors was proposed in this paper based on the analysis of flux and torque ripples in the traditional DTC. In this method, voltage vector pairs was selected using torque and flux errors, the action time of basic voltage vectors was determined using the flux position and torque errors and new voltage vectors were compounded to control motors. Simulation results show that compared with the traditional DTC, the new DTC based on fixed action time of vectors can effectively reduce flux and torque ripples and not increase the complexity of control systems, which apparently improve the control performance.