An adaptive sliding-mode observer for induction motor sensorless speed control

An adaptive sliding-mode flux observer is proposed for sensorless speed control of induction motors in this paper. Two sliding-mode current observers are used in the method to make flux and speed estimation robust to parameter variations. The adaptive speed estimation is derived from the stability theory based on the current and flux observers. The system is first simulated by MATLAB and tested by hardware-in-the-loop. Then, it is implemented based on a TMS320F2812, a 32-bit fixed-point digital signal processor. Simulation and experimental results are presented to verify the principles and demonstrate the practicality of the approach.