A robust rotor time constant estimation method for vector control of induction motor under any operating conditions

This paper proposes a novel rotor time constant estimation method for the vector control of an induction motor, which is effective for both load and no-load conditions. The approach is based on regulating the variation of the magnetizing energy stored in the magnetizing inductance to a suitable assigned value. The proposed estimation method is completely robust to the stator resistance and magnetizing inductance. Moreover the method has excellent performance under low speeds because a pure integrator circuit is not used in the method. The effectiveness and the characteristics of the proposed method are investigated by experiment and simulation