Experimental Validation of Coupled Circuit Model and Simulation of Eccentric Squirrel Cage Induction Motor

Abstract

Squirrel Cage induction motors are manufactured and designed to meet the performance criteria depending on the type of loadings and duty cycle. A detailed model of the induction motor describing the actual layout and geometry of the stator phase windings and rotor bars is essential for the simulation and analysis of induction motor under fault mode of operation. The performance of the motor depends on actual physical construction of the motor. Even a newly manufactured motor may have unequal stator phases, rotor bars and non uniform air-gap. This paper addresses simulation and experimental validation of coupled circuit model useful for asymmetrical as well as fault mode operation of three phase squirrel cage induction motor. A new three phase squirrel cage induction motor is considered for the validation of the coupled circuit model under healthy condition. The model parameters are determined experimentally or calculated from motor geometry. The magnetizing inductances are calculated using winding function method. The model is used for the simulation of air gap eccentricity mode of motor operation. Fault diagnosis methods use either current, flux, vibration, speed or temperature for the diagnosis of internal faults. Therefore, analysis of these variables is essential for the understanding, design and implementation of internal fault diagnosis.