永磁同步电机有限集模型预测直接转矩控制

针对永磁同步电机(PMSM)模型预测直接转矩控制(DTC)转矩脉动大、功率元件开关频率不恒定等问题,将两电平逆变器的8个电压空间矢量作为有限控制集,应用到PMSM DTC中。设计考虑转矩误差、最大转矩电流比及电流约束的成本函数,利用成本函数来估算有限集合中各电压矢量的占空比,从而求得逆变器的最优电压矢量作为系统控制量。与传统模型预测控制方法相比,该方法的电流谐波和转矩脉动显著降低,且转矩动态性能也得到改善。仿真试验结果验证了所提出的控制方案有效性。

Direct Torque Control of PMSM with Modified FCSMPC

The model predictive direct torque control (DTC) of permanent magnet synchronous motor (PMSM) system had many problems, such as large torque ripple, constant switching frequency. A new scheme of direct torque control for PMSM based on finite control set model was proposed. The eight voltage vectors of the twolevel converter were utilized as a finite control set for the torque prediction of the PMSM. A cost function considering the torque error, the maximum torque per ampere and the current limitation was introduced. The cost function was used to estimate the duty cycle of each voltage vector. Thus the optimal voltage vector could be obtained from eight voltage vectors and their duty cycles. Compared with the traditional model predictive control, the proposed method had small harmonic current and torque ripple, and had excellent dynamic performance. Simulation results were presented to verified the performance of the proposed control scheme.