Diagnosis of induction motor rotor broken bars

The results of a comparative experimental investigation of various media for noninvasive diagnosis of rotor faults in three-phase induction machines are presented. Stator voltages and currents in a squirrel three-phase induction motor are measured, recorded and used for computation of the partial and total input powers. The different waveforms of the stator current, partial input power and total input power are subsequently analysed using the fast Fourier transform (FFT) to detect the incipient rotor fault with high accuracy.