On-line rotor time constant estimation for indirect field oriented induction machine

This paper proposes an on-line rotor time constant estimation method for an indirect field oriented induction machine. The performance of indirect field oriented control is dominantly dependent on the rotor time constant which is varying according to the temperature. Therefore, the on-line rotor time constant estimation is inevitable to guarantee a competent performance in the indirect field oriented induction machine drive. The proposed method designs the compensator to which the integration term in a proportional and integral (PI) current regulator and the current are inputted for estimating the time-varying rotor time constant. The proposed method has a simple structure and is available for the wide speed and torque range operations in the various industrial fields. In this paper, the effectiveness of the proposed method was verified with experimental results.