基于预测控制的SPMSM直接转矩控制最优电压矢量选择策略

Optimum Voltage Vector Selection Strategy for Direct Torque Control of Surface Permanent Magnet Synchronous Motor Based on Predictive Control

针对传统开关表实现的表贴式永磁同步电机直接转矩控制中不合理转矩脉动的问题,提出了最优电压矢量选择策略。依据电压矢量对转矩和磁链的作用规律得到电压矢量选择区间表,建立了磁链和转矩误差成本函数,基于预测控制对区间内的电压矢量进行最优选择,并采用空间矢量调制技术实现。仿真结果表明:所提最优电压矢量选择策略可完全消除因开关表选择电压矢量不当引起的不合理转矩脉动,使得转矩平均误差降低58%、峰值误差降低67%,定子磁链幅值均值误差降低28%、峰值误差降低53%,同时由于采用了空间矢量调制技术,从而使得逆变器开关频率恒定。

The optimal voltage vector selection strategy was proposed for the problem of unreasonable torque ripple in direct torque control of surface permanent magnet synchronous motor realized by traditional switch table.According to the law of voltage vector and flux linkage,the voltage vector selection interval table was obtained,and the cost function of flux linkage and torque error was established. Based on the predictive control,the voltage vector in interval was selected optimally,and achieved by the space vector modulation technique. The simulation results showed that the optimal voltage vector selection strategy proposed can completely eliminate the unreasonable torque ripple caused by the improper selection of the voltage vector of the switch table,the average error of the torque was reduced by 58% and the peak error was reduced by 67%,the average error of the stator flux decreases by 28% and the peak error was reduced by 53%. At the same time,the use of space vector modulation technology makes the inverter switching frequency constant.