不同开关表下PMSM直接转矩控制性能仿真研究

Simulation Study on Control Performance of PMSM-DTC under Different Switching Tables

直接转矩控制(DTC)下永磁同步电动机(PMSM)运动系统中,逆变器输出电压矢量时会产生高频共模电压,DTC双闭环Bang-Bang控制结构也会造成电流谐波畸变与转矩的高频脉动。在Matlab/Simulink中建立其仿真模型,分别采用6矢量和7矢量开关表,并比较控制性能、电流、转矩和共模电压的变化,仿真结果表明两者动态性能相近,然而7矢量开关表控制相对于6矢量开关表而言,对电流谐波畸变以及转矩频谱中非基频分量都有所抑制,但同时增大了共模电压。该分析结果为逆变器在各种应用场合下控制输出方式的选择提供了参考依据。

In the motion system of permanent magnet synchronous motor （PMSM） under direct torque control （DTC）, the inverter produces high-frequency common-mode voltage （CMV） based on the switching table when outputting voltage vectors, and its double-closed-loop Bang-Bang control structure also causes current harmonic distortion and high-frequency ripple of the torque. A simulation model is established for PMSM motion system under DTC based on Matlab/Simulink using different switching tables, where performance and CMV between 7 vectors and 6 vectors switching tables are compared respectively. The results demonstrate that both have similar dynamic performance; relative to 6 vectors switching table, 7 vectors switching table suppresses current harmonic distortion and non-fundamental frequency of torque spectrum better, while the CMV increases at the same time. The analysis results can serve as a reference for the choice of actual inverter output mode.