An effective identification of rotor resistance for induction motor vector control

Nowadays, vector control induction motor have gained wide acceptance in high performance applications. Crucial to the success of the indirect vector control is the knowledge of the instantaneous position of the rotor flux. This requires a priori knowledge of rotor time constant which varies with rotor temperature. So, the variations of rotor circuit time constant can cause significant performance deterioration if no means for compensation or identification is applied. In this paper, an approach to estimating rotor resistance variations for induction motor vector control via temperature is proposed. In essence, the approach uses sensors to detect temperature, which is then used to determine the correct values of rotor resistance. From results, it is verified that the proposed approach can overcome the problem of performance degradation due to rotor resistance variations. The method is applicable for the design of a gain scheduling ac drives to optimize their performance