Design of robust controller for AC asynchronous motor

The control performance of AC asynchronous motor under vector control will be affected seriously by uncertainty. In order to improve the robust stability and robust criteria, based on the conventional vector control and from frequency domain, robust speed and flux controller are designed by loop shaping method. Meanwhile, Elman network is used as flux estimator for the sake of the difficulty in measuring flux accurately. Simulation results show: when the dead-time disturbance is added in the system, the system with robust controllers improves robust performance obviously compared with the system with PI controllers; when the motor parameters vary, the system can achieve good speed tracking.