Rotor resistance estimation for induction motor using model reference adaptive controller

Variable speed drives for induction motor cause both fast torque response and wide operating speed. Indirect vector control of induction motor is a predictive method, where the speed of the rotor flux is predicted from rotor speed and slip speed variation. The rotor speed may be obtained either from speed sensors or from the estimation method. Model reference adaptive system controller utilizing the reactive power is presented for the online estimation of the rotor resistance to maintain the flux orientation in an indirect vector control of induction motor. The effect of sudden and slow variation in rotor resistance on performance of the indirect vector controlled induction motor drive is investigated. Reactive power based model reference adaptive controller estimator is less sensitive to integral problems like saturation and drift. Simulation and analytical analysis have been presented in MATLAB/Simulink to validate the capability of the technique.