Air-gap power and rotor loss estimation for induction motor efficiency monitoring based on Kalman filtering

This paper presents a technique of induction motor´s efficiency monitoring based on air-gap power and rotor loss estimation by Kalman filtering. A simplified model of three phase induction motor, with equivalent circuit of five elements, has been tested by the proposed technique with varying load torque and power to represent practical operations. Good agreement between the simulation and experimental results are found in a normal operating range of load torque and power.