双三相永磁同步电机模型预测电流控制研究

Research on Model Predictive Current Control of Dual Three Phase Permanent Magnet Synchronous Motor

六相逆变器为双三相永磁同步电机提供了丰富的电压矢量资源,能够使预测电流控制变得更加精准,但更多的电压矢量会带来算法计算量过大的问题,同时双三相电机的谐波电流会使电机的损耗增加,需要对其进行抑制。提出了一种改进的模型预测电流控制方法。利用最外围大矢量与次外围中矢量在z1z2子平面方向相反的特性,在一个控制周期内将两个矢量按照相应比例结合并作用于电机,可实现抑制谐波电流的目的。根据定子磁链所在扇区的位置确定出更小范围内的8个预测电压矢量,从而减少了系统运算量。同时以d,q轴电流误差项作为价值函数,消除z1z2子平面的电流误差项,如此可避免权重系数的整定。通过实验对所研究方法进行了验证,结果表明所提MPCC方法可以有效地降低谐波电流,并且具有良好的控制性能。

Six phase inverter provides abundant voltage vector resources for dual three-phase permanent magnet synchronous motor,which can make predictive current control more accurate.However,more voltage vectors cause the problem of too much calculation.At the same time,the harmonic current of dual three-phase motor will increase the motor loss,which needs to be suppressed.Therefore,an improved model predictive current control(MPCC)algorithm was proposed.According to the characteristic that the largest vector of the outermost region is opposite to the middle vector of the sub periphery in the z1z2 sub-plane,the two vectors were combined according to a certain proportion to act on the motor in a control cycle to suppress the harmonic current.Furthermore,the stator flux linkage position was observed and the predicted voltage vector was determined according to its sector.The predicted voltage vectors were reduced to 8.The d,q axis current error term was used as the value function to eliminate the current error term of z1z2 sub-plane,so as to avoid the setting of weight coefficient.The results show that MPCC can effectively reduce the harmonic current and has good control performance.