基于电流偏差的永磁同步电机滑模电流解耦控制

Decoupled current control of permanent magnet synchronous motors drives with sliding mode control strategy based on current deviation

永磁同步电机(PMSM)矢量控制的目标是使PMSM表现优良的动态性能和稳态性能,为解决同步旋转坐标下dq轴电流存在耦合,同时传统解耦方法在电感参数失配时解耦效果不佳的问题,提出一种基于电流偏差的永磁同步电机滑模电流解耦控制方法.该方法在电流偏差解耦控制电机模型的基础上,保证系统的良好的动态性能,并充分利用偏差解耦结构的灵活性,引入新的Z控制函数,设计滑模控制律,使其运动在滑模阶段,并且呈非线性光滑特性,以保证系统滑动模态,抑制抖振,从而实现dq轴电流较好的解耦效果,同时提高系统在整个运动过程中因参数摄动和外在扰动的鲁棒性,保证系统的动态性能.通过对传统解耦方法和新方法的仿真和实验对比分析,验证所提方法的可行性和有效性.

The purpose of field-oriented control(FOC) is to guarantee perfect dynamic and steady performance of permanent magnet synchronous motors(PMSM). In order to solve the problem that the dq axis current coupling exists in the synchronous rotating frame and the traditional decoupling method has poor decoupling effect when the inductance parameters are mismatched, therefore a new decoupling control using sliding mode based on current derivation was proposed.The method ensures good dynamic performance of the system on the basis of a current deviation decoupling control motor model, fully utilizes the fiexibility of a deviation decoupling structure, introduces a new Z control function, and designs a sliding mode control law, which guarantees the movement of the sliding mode phase with smooth and nonlinear characteristics, so as to ensure the sliding mode of the system and inhibit chattering, as well as to realize better decoupling effect of the dq axis current, simultaneously improve the robustness of the system in the whole motion process due to the parameter perturbation and the external disturbance, and ensure the dynamic performance of the system. The feasibility and the effectiveness of the proposed method are verified by the simulation and experimental analysis of the traditional decoupling method and the new method.