In order to improve the chattering problem in the traditional sliding mode observer, this paper proposes an adaptive gain sliding mode observer which can update the sliding mode gain adaptively according to the system state. This effectively suppresses chattering in the traditional sliding mode observer and improves the estimation accuracy of the flux and speed. This adaptive gain sliding mode observer is then combined with the model predictive flux control so as to improve the practicability of the latter. At the same time, for reducing the influence of speed estimation error on speed sensorless model predictive flux control, this paper improves the rotor flux prediction model in it. The simulation results justify the proposed theory.

Adaptive gain sliding mode observer, induction motor, model predictive flux control, speed sensorless.