Sensorless rotor time-constant and mutual inductance estimation for induction motor drive systems

In this work, a sensorless estimation algorithm based on the recursive least squares method is presented. It estimates the induction machine rotor time constant and the mutual inductance. The presented algorithm is designed to operate in parallel to the control algorithm. Its adoption can benefit all control techniques that are influenced by machine parameter deviations. Usual vector controlled applications which demand a speed sensor as well as sensorless based control schemes can utilize this algorithm to improve their dynamic and steady state performance. All mathematical developments are shown. Some simulation results are presented to verify the effectiveness of the proposed estimation algorithm.