A novel adaptive vector control system for temperature compensation in induction motors

A new method for the improvement of temperature variation in induction motor (IM) speed control is presented in this paper. A direct measurement of the rotor temperature is assumed. The compensation of the temperature effect is made not only by adjusting a digital filter flux model coefficients but also by calculating the on-line proportional integral (PI) controller coefficients. These corrections yield matching of the flux model and the induction motor model, consequently the magnitude of the reference rotation and the induction motor model angles are equal so the matching of the command estimated variables and the real variables of the induction motor is obtained. This method uses the direct field-oriented vector control and eliminates its main disadvantage which is the decoupling of flux and torque when a rotor time constant varies. The simulations have shown an improvement mainly in the transient state response