Sensorless sliding mode control method for a three-phase induction motor

This paper improved a sensorless sliding mode control strategy for the three-phase induction motor system. Based on the decoupled control scheme, two sliding mode controllers for the flux and rotor speed are the main control method for the tracking control. In the proposed sliding mode strategy, the sliding mode surfaces as the nonlinear exponential function are applied to reduce the chattering phenomena. The requirement of the rotor speed is relaxed by the observer based neural networks estimator. In addition, the online updating algorithm for the speed observer and the SMC control laws are obtained in the sense of the Lyapunov stability theorem. Therefore, the stability, robustness and tracking control features are guaranteed. The effectiveness of the proposed control system is demonstrated by comparative simulation and experiment results for the three-phase asynchronous induction motor 1 hp.