基于MPC的PMSM转矩电流误差控制研究

Research on Torque Current Error Control of PMSM Based on MPC

针对占空比双矢量模型预测电流控制方法采取无差拍思想计算占空比时,周期内较大的电流误差导致转矩脉动严重的问题,提出了一种矢量切换的方法。所提方法不以无差拍思想下转矩电流预测值与参考值相等为控制目标,而是通过改变电压矢量的切换时刻并保证电流误差正负对称相等,实现了降低转矩电流控制误差的目的。通过推导占空比,对比分析了矢量切换前后单个控制周期内的最大电流误差。并在Simulink仿真平台上验证了矢量切换方法,同时与占空比双矢量方法进行对比。结果表明矢量切换方法能有效减小周期内转矩电流跟踪误差,实现了每个周期过程最优控制。

In order to solve the problem that the torque pulsation is serious due to the large current error in the period when the duty cycle is calculated by the dead beat method in the duty cycle dual-vector model predictive current control method,a vector switching method is proposed.The control objective of the proposed method is not to equate the predicted torque current with the reference value under the deadbeat idea,but to reduce the torque current control error by changing the switching time of the voltage vector and ensuring the symmetry of the positive and negative current errors.By deducing the duty cycle,the maximum current errors in a single control cycle before and after vector switching are compared and analyzed.The vector switching method is verified on the Simulink simulation platform and compared with the duty cycle double vector method.The results show that the vector switching method can effectively reduce the intra-cycle torque current tracking error and realize the optimal process control in each cycle.