Finite Element Analysis of the Noninvasive Detection and Evolution of Faults in a High Power Induction Motor through Neighboring Coil Sensors

Having as subject of investigation a high power (1 MW) squirrel cage induction motor this paper deals with finite element models step by step in time domain for the detection and evolution of the faults short-circuit in the stator winding, static eccentricity and rotor broken bar. The signatures of these faults in the voltages of coil sensors placed in the motor neighboring are analyzed in order to offer solutions for the noninvasive detection of the fault appearance and of the evolution of faults. The rms values and the amplitudes of the most important harmonics of the voltages of one coil sensor, respectively of two coil sensors series differential connected are investigated in order to establish the best solution for the monitoring of the motor healthy state.