Secondary Resistance Identification of an Induction-Motor Applied Model Reference Adaptive System and Its Characteristics

Induction-motor torque is not accurately controlled when the estimated secondary resistance of an induction-motor model in a vector controller differs from the true secondary resistance. An algorithm which identifies the secondary resistance on-line is developed. The motor operating condition for secondary resistance identification, the stable identifier organization, and the experimental investigation confirming the identification algorithm performance are presented. The algorithm is based on the theory of model reference adaptive systems (MRAS). The proposed algorithm stably identifies the secondary resistance under any load and any speed when a sinusoidal signal is injected into the flux axis primary current. The vector controller adopting this algorithm controls motor torque accurately under any load and any speed.