六相串联三相双PMSM系统无权重系数MPTC

MPTC Without Weighting Factors for Six-phase and Three-phase PMSM Series-connected System

针对六相串联三相双永磁同步电机(PMSM)系统提出了一种无权重系数的模型预测转矩控制(MPTC)策略,使用基于六相相电压误差的成本函数以消除传统成本函数中的权重系数。基于两台PMSM转矩方程的微分表达式和定子电压方程得到两台PMSM的期望电压矢量,同时由零序电流比例积分(PI)调节器得到期望零序电压,最后通过矩阵T6得到期望六相相电压。为抑制零序电流和缩短控制策略的计算时间,根据期望零序电压的大小,仅预选最多20个电压矢量代入到成本函数中优选出最优电压矢量。实验结果表明,所提控制策略独立解耦控制两台PMSM,同时实现两台PMSM转矩及定子磁链幅值的精确跟踪和零序电流的有效抑制。

A model predictive torque control(MPTC)strategy without weighting factors is proposed for the six-phase and three-phase permanent magnet synchronous motor(PMSM)series-connected system.Cost function based on six-phase voltage error is used to eliminate the weight factors in the traditional cost function.Based on the differential expression of two PMSMs torque equations and the stator voltage equation,the expected voltage vectors of two PMSMs are obtai ned.Mean while,the expected zero-sequence voltage is obtained from the zero-sequence current proportion integral(PI)regulator.Finally,the expected six-phase voltage is obtained through the matrix T6.In order to suppress the zero-sequence current and shorten the calculation time of the control strategy,only up to 20 voltage vectors are preselected and substituted into the cost function to select the optimal voltage vector.Experimental results show that the proposed control strategy independently decoupling control two PMSMs,simultaneously realize the accurate tracking of the torque and stator flux amplitude of the two PMSMs and the effective suppression of the zero-sequence current.