A robust speed controller with smith predictor for a PMSM drive system with time delay

In this paper, using H∞control theory, a robust speed controller with smith predictor is proposed to improve the speed control performance of the permanent magnet synchronous motor (PMSM) servo system with time delay. The robust speed controller is designed to improve the robustness of control system. Meanwhile, considering the time delay of the system, the speed controller combined with smith predictor is used to compensate the impact of system time delay. Firstly, based on theH∞state space (time domain) method, a robust speed controller is established, which has simple structure and easy to be realized. Secondly, theH∞robust standard design problem is transformed to an optimization solution of the linear matrix inequalities (LMIs). Thirdly, a smith predictor is stalled at the parallel position of the robust speed controller, which is of great help to improve the performance of the servo system with time delay. Finally, simulation results demonstrate that compared with traditional PI controller, the novel robust controller has better control performance and the robust controller with smith predictor is effective for the PMSM drive system with time delay.