基于SVPWM的永磁同步电动机直接转矩控制

Direct Torque Control of Permanent Magnet Synchronous Motor Based on SVPWM

针对永磁同步电动机(PMSM)传统直接转矩控制(DTC)系统中磁链和转矩脉动大的问题,研究基于电压空间矢量脉宽调制(SVPWM)策略的PMSM DTC。给出PMSM在αβ坐标系下的数学模型,然后结合SVPWM原理,在定子磁链ψs幅值保持恒定的情况下,通过控制转子磁链ψs和定子磁链ψs间负载角δsm的增量Δδsm来控制电磁转矩T e的增量ΔT e,从而达到控制电动机转速的目的。在Matlab/Simulink仿真环境下,对该控制系统进行了建模和仿真,与传统DTC系统比较,该方法具有更好的动、静态性能,定子两相电流的正弦度更好,磁链和转矩脉动明显减小。

Aimed at the problem of large flux linkage and torque pulsation in traditional direct torque control （DTC） system for permanent magnet synchronous motor （PMSM）, the PMSM DTC based on voltage space vector pulse width modulation （SVPWM） strategy was re- searched. This paper firstly gives the mathematical model of PMSM inα-β coordinate system. Combined with SVPWM principle, in the case of stator flux amplitudeψs remaining constant, the electromagnetic torque increment ATe was controlled by controlling increment a △δsm of load angleδsm between rotor flux linkageψf and stator flux linkageCs, thus the purpose of con- trolling motor speed was achieved. The proposed system was modeled and simulated in Matlab/ Simulink environment. Compared with traditional DTC system, it is shown that this method has better dynamic and static performances, better sinusoidal wave of two-phase stator current and significant reductive flux linkage and torque pulsation.