An adaptive sliding mode observer for induction motor sensorless speed control

An adaptive sliding mode flux observer is proposed for speed sensorless vector control of induction motors. Two sliding mode current observers are used in the method to make flux and speed estimation robust to parameter variation. Adaptive speed estimation is derived from the stability theory. The stability of adaptive flux observer is guaranteed by Lyapunov stability theory. The system is first simulated by MATLAB and HIL (hardware-in-the-loop). Then it is implemented based on TMS320F2812, a 32-bit fixed-point DSP controller. Simulation and experimental results are presented to demonstrate the potentials and practicality of the approach.