基于相电流重构的永磁同步电动机直接转矩控制

摘要

对永磁同步电动机控制系统来说,只使用一个直流母线侧电流,传感器来估计三个相电流,可以最大限度地减少电流传感器的个数,从而降低成本,并减小电机的体积和重量.以往电流重构的过程中对开关过程过分依赖,若对某些电流采样失效的特殊区域处理不当将造成电压损失.提出了一种新的相电流重构方法,根据永磁同步电动机的动态方程以及不同开关状态时直流侧代表不同相电流的特性,将两者结合来重构相电流.该方法降低了对开关状态的依赖,提高了相电流重构精度.仿真实验证明,该方法重构出的相电流值具有高度准确性.%For PMSM' s control system,the number of current sensors can been minimized by only using DC bus current sensor to estimate the three-phase current,which reduce cost and the size and weight of motor. Reconstruction was over reliance on switch state in the past. Voltage loss was caused by inadequately processed in some special area of the current sample. A new phase current reconstruction method was presented,which reconstructed by combination of PMSM's dynamic equations and the theory that at different switch state DC current represent different phase current. The dependency of the switch state was reduced,and the accuracy of the phase current reconstruction was improved. The simulation results show that this method of phase current reconsturction has high accuracy.