Robust vector control of induction motor without using stator and rotor circuit time constants

To solve the problem of performance degradation due to parameter variations in an indirect vector control of an induction motor, a novel and simple estimation method for the rotor circuit time constant is presented. The proposed method is based on regulating the energy stored in the magnetizing inductance, which can be calculated from the terminal voltages and currents. From theoretical and experimental results, it is verified that the proposed method can overcome the problem of performance degradation due to parameter variations without the necessity of knowing the values of stator resistance and rotor circuit time constant at all