关键词: 永磁同步电动机, 拓展控制集, 模型预测转矩控制, 离散空间矢量调制, 虚拟电压矢量

Abstract: To solve the problems of large computational load and large torque ripple in the traditional model predictive torque control (MPTC) for permanent magnet synchronous motors,this paper proposes an improved MPTC method based on an extended control set. To reduce the computational burden,a simplified search method based on the deadbeat principle is proposed to reduce the number of candidate voltage vectors in the control set expanded by using discrete space vector modulation. The proposed method determines the optimal sector by the minimum cost function of the center voltage vector and divides the optimal sector into three regions according to the amplitude of the reference voltage vector, effectively narrowing the optimization range and candidate voltage vectors,thereby simplifying the complexity of the suboptimal voltage vector selection process. To reduce torque ripple, the suboptimal voltage vector obtained by the simplified optimization method is second stage optimization. After determining the region, it is combined with the virtual voltage vector set with variable amplitude according to its own region rules. The new vector set and the suboptimal voltage vector are optimized again to make the output optimal voltage vector closer to the actual control solution. Experimental validation is conducted to verify the effectiveness of the proposed method,the results confirm its core merits of lower computational burden and better steady-state performance.

Key words: permanent magnet synchronous motor, extended control set, model predictive torque control, discrete space vector modulation, virtual voltage vector