Sensorlesse variable structure adaptive speed control of an induction motor

This paper presents an algorithm for speed controlled of the induction motor under sensorless. According to the Lyapunov stability theory, applying the vector analysis method, through the stator current and the rotor flux are calculated then rotor speed is estimated. In order to overcome the uncertainty of system parameters and the external load disturbance, the sliding mode surface is designed based on robustness requirements. Variable structure adaptive control to track motor speed is fulfilled finally. The simulation result shows that the control scheme is effective.