Comparison of flux and real power based MRAS for inverse Rotor time constant estimation in induction Motor Drives

The performance of Vector Controlled Induction Motor (IM) Drives to a large extent depends on the accuracy of inverse rotor time constant (1/T_r) estimation which in turn mainly depends on the value of rotor resistance which vary with temperature. Generally, MRAS techniques are widely used for 1/T_r estimation. In this paper, Rotor Flux based MRAS (RF-MRAS) and Real Power based MRAS (RP-MRAS) for 1/T_r estimation is designed and validated through simulation. The performance of these two methods are analyzed extensively and compared in terms of accuracy, settling time and computational complexity. The suitable method of 1/T_r estimation for induction motor drive is identified. The interesting results obtained are presented.