Rotor Resistance Estimation for Predictive Maintenance of Sensorless Induction Motor Drives

Broken bars and end-rings are common faults in three phase induction motors. These faults lead to unsymmetrical magnetic field, generate noise and vibration, increase temperature and the motor may be destroyed. In this paper, a rotor resistance estimator has been proposed for detecting faults while they are still developing or adequate warning of imminent failure and to give minimum downtime and optimum maintenance schedules. The rotor resistance has been estimated in order to apply in sensorless IM drives. A parallel model reference adaptive system (MRAS) has been proposed in order to simultaneous estimation of the rotor resistance and rotor speed. The aim of the proposed MRAS is to save the cost of implementation and the processes time. The proposed parallel MRAS depends on the point of slowly variation of the rotor resistance with respect to the rotor speed. The performance of the proposed scheme has been verified through computer simulations. The simulation results confirm that the proposed algorithm is effective. Also, an accurate estimation of rotor resistance and speed is achieved under different operation conditions s