基于改进内模控制的永磁同步电机电流环设计

Design of Improved Internal Model Control for Current Loop of Permanent Magnet Synchronous Motor

永磁同步电机(PMSM)作为一种高阶非线性系统,由于参数摄动和外部干扰的原因,传统内模控制器不能保证其精确的控制要求。在传统内模控制的基础上,设计了一种基于指数收敛的误差干扰观测器。在解耦和反电动势补偿情况下,建立内模控制器,然后由内模控制器的输出和反馈电流,构造误差干扰观测器的状态方程,输出误差补偿信号,补偿电机运行过程中参数变动和干扰因素,实现PMSM的高精度控制。建立MATLAB/Simulink仿真模型,仿真中人为增加不确定量和扰动。仿真结果表明,在存在不确定信号和负载扰动时,采用改进的内模控制可以实现电流补偿,降低电流纹波,减小电流稳态误差,同时提高转速响应速度,降低扰动误差。

Permanent magnet synchronous motor （PMSM） was considered as a high order nonlinear system due to the parameter uncertainties and external disturbances. Superior control performance could not be guaranteed by using internal model control （IMC）. An exponential convergence control-based observer was derived to estimate uncertainties. An internal model was set up under the condition that coupling term and back electromotive force were compensated completely. Then, a state-space model for observer was constructed based on output term of IMC and feedback current. Finally the prediction error was obtained to estimate uncertainties. The system was simulated by MATLAB / Simulink. Simulation results showed that by using improved internal model control （IIMC）, the disturbance observer could realize the current compensation, suppress the current ripple, reduce the steady-state error, and improve the response of speed, reduce the fluctuation of speed error under load disturbance.