基于梯度下降法的永磁同步电机单电流弱磁优化控制

摘要

Considering the fact that single current weakening control methods cannot guarantee optimum motor efficiency in high-speed field-weakening control of interior permanent magnet synchronous motors ( IPMSM),this paper proposes a novel weakening control method based on gradient descent by using single current regulator. On the basis of single current control,this online method automatically optimizes the corrected q-axis voltage by comparing the current gradient descent direction and the constant torque direction of the load and speed respectively, so that the current reaches the minimum to improve operational efficiency. It is also proved that the optimal result of this problem is unique and optimal. Finally,the motor simulation and experiment platforms based on Simulink and dSPACE are set up to demonstrate the superiority of this method compared with traditional weakening control methods. The results show that the proposed method can improve the efficiency of the permanent magnet synchronous motor in the high speed region,which provides an effective way for the efficient operation of the system.%针对目前的单电流弱磁控制方法无法实现内置式永磁同步电机高速区运行效率最优的问题，提出一种基于梯度下降的单电流弱磁优化控制方法。首先在分析单电流弱磁控制思想的基础上，根据电机运行点恒转矩方向在电流下降梯度上的投影关系，在线寻优修正交轴电压使其工作电流达到最小值，从而实现了系统效率的提升；同时证明了梯度下降方法在解决内置式永磁同步电机弱磁优化控制问题时结果的惟一性；最后分别搭建了基于Matlab/Simulink和dSPACE的仿真与试验平台，与现有弱磁优化方法的对比试验研究结果表明，该文提出的方法可提高内置式永磁同步电机高速区的运行效率，为系统的高效运行提供了有效途径。