Stator Resistance Estimation Utilizing Real and Reactive Power for Direct Torque Controlled Induction Motor Drives
In this paper, a new method is proposed to estimate the Stator Resistance for direct torque control of Induction Motor. Direct Torque control of Induction Motor (IM) requires accurate estimation of torque, flux angle and resultant flux and these signals in turn depends on the motor flux. The flux is generally estimated using voltage model equations. The voltage model equation to a large extent depends on the accuracy of stator resistance of the induction motor. The stator resistance varies due to temperature during motor operation. Hence a method based on the active and reactive power is proposed for stator resistance estimation. The effect of stator resistance variation on the flux, torque and flux angle is studied and the results obtained are presented. The proposed method of stator resistance estimation is shown to track the various %changes in stator resistance with good accuracy.