Speed sensorless PWM robust control of induction machines

The design of a speed sensorless PWM robust control scheme for an induction motor drive in order to control the rotor speed is proposed. The proposed design is divided in two parts. In the first one it is designed a speed estimator to estimate the rotor speed. In the second one it is developed the proposed robust control. This robust control comprises two parts, the so called inverse dynamic technique that linearizes and decouples the dynamic equations of the induction motor and the variable structure speed controller, that makes the design robust against parameter variations and external disturbances. Finally, the stability of the proposed control law is demonstrated using the Lyapunov stability theory and the performance of the proposed control system is demonstrated by means of simulation examples.