双三相永磁同步电机的双矢量模型预测转矩控制

Two vectors based model predictive torque control of dual three phase permanent magnet synchronous motor

双三相永磁同步电机的传统直接转矩控制仅采用αβ子平面的外围电压大矢量,会导致较大谐波电流,并且直接转矩控制存在固有的磁链和转矩波动较大的问题。本文提出一种双电压矢量模型预测转矩控制策略。扩大电压矢量选择范围,根据次外围矢量与最外围矢量在z_(1)z_(2)子平面方向相反的特性增选次外围矢量,通过分配这两组矢量作用时间,使得谐波子平面的电压幅值为零,实现谐波电流抑制。降低系统计算量,根据定子磁链所在位置,将12个预测电压矢量减少至4个。进一步地采用控制预测模型估算出下一时刻的转矩值和磁链值,利用价值函数在线选出最优的一组电压矢量,使得作用的电压矢量更加准确有效。所提方法抑制了谐波电流,并达到减小转矩和磁链波动的目的,通过仿真和实验验证了该算法的可行性和有效性。

The conventional direct torque control of dual three phase permanent magnet synchronous motor only employs the outermost voltage vector of theαβsub-plane,which leads to a large harmonic current,and the direct torque control has the inherent problems of large flux and torque fluctuation.A two voltage vectors model predictive torque control strategy was proposed.The selection range of voltage vector is expanded.According to the characteristics of the sub-peripheral vectors and the outermost vectors in the direction ofz_(1)z_(2) sub-plane,the sub-peripheral vectors was added.By allocating the two groups of vector action time,the voltage amplitude of harmonic sub-plane is zero,and harmonic current suppression can be realized.The system calculation is reduced,and 12 predicted voltage vectors are reduced to 4 according to the position of stator flux.Furthermore,the torque value and flux value of the next time were estimated by using the prediction model.The optimal group of voltage vectors was selected online by using the value function,which makes the selected voltage vector more accurate and effective.The proposed method can suppress harmonic current and reduce torque and flux fluctuation.Feasibility and effectiveness of the algorithm were verified by simulation and experiment.