一种基于空间矢量调制的永磁同步电动机新型直接转矩控制方案

针对永磁同步电动机(PMSM)的传统直接转矩控制(DTC)中存在的磁链转矩脉动大和开关频率不恒定等问题,分析了直接转矩控制中影响磁链和转矩增量大小的因素,在建立定子磁链坐标系下永磁同步电动机数学模型的基础上,提出了一种基于空间矢量调制(SVM)的新型DTC方法,该方法利用定子电压在定子磁链坐标轴上的分量控制电动机的磁链和转矩,再结合空间矢量调制方法控制逆变器运行。仿真和实验结果证明了这种基于空间矢量调制的直接转矩控制方法可以有效地减小传统直接转矩控制中的磁链和转矩脉动,并使逆变器工作在恒定的开关频率下。

A Novel Direct Torque Control Scheme for Permanent Magnet Synchronous Motors Based on Space Vector Modulation

To solve the problems of large flux and torque ripples and inconstant switching frequency in direct torque control (DTC) for permanent magnet synchronous motors (PMSM), factors of affecting flux and torque increments are analyzed in DTC. Based on the PMSM models in the coordinate of stator flux linkage, a novel DTC method based on space vector modulation (SVM) is proposed. In this method flux and torque are controlled through stator voltage components in stator flux linkage coordinate axes and space vector modulation is used to control inverters. Simulation and experimental results verify that this scheme could effectively decrease flux and torque ripples and make inverters have constant switching frequency.