永磁同步电机改进弱磁策略

An Improved Flux-weakening Control Strategy of PMSM

常规矢量控制方式下永磁同步电机调速系统不会对电机气隙主磁场作弱磁调理,限制了永磁同步电机调速能力。采用电压反馈弱磁能够提升PMSM的调速能力,但是传统弱磁控制策略在深度弱磁区域给定的电流较大,容易导致实际电流无法跟踪给定电流,电流与输出转矩波动大,甚至存在调速系统失控的风险。改进后采取在深度弱磁区域中加入q轴电流误差积分的弱磁控制环节。仿真和实验验证了改进后的弱磁控制策略能够有效地抑制电流和转矩的波动问题。为了进一步改善电机速度响应性能,速度环采用模糊PI控制器,减小速度响应时的超调量和调节时间。

In the application of new energy vehicles, it is hoped that the motor has the widest possible speed range under the rated power. The permanent magnet synchronous motor(PMSM, Permanent Magnet Synchronous Motor) speed control system of conventional vector control mode does not perform field weakening adjustment on the main magnetic field of the motor air gap, which limits the speed control capability of the permanent magnet synchronous motor. The use of voltage feedback field weakening can improve the speed regulation capability of PMSM, but the traditional field weakening control strategy gives a large current in the deep field weakening area, which easily leads to the fact that the actual current cannot track the given current, and the current and output torque fluctuate greatly, and even there is a risk of losing control of the speed control system. This paper adopted the field weakening control link that adds q-axis current error integral in the deep field weakening area. Simulations and experiments verify that the improved field weakening control strategy can effectively suppress current and torque fluctuations. In order to further improve the speed response performance of the motor, the speed loop adopts a fuzzy PI controller to reduce the overshoot and adjustment time during the speed response.