Comparative Investigation of Diagnosis Media of Stator Voltage Asymmetry and Rotor Broken Bars in Induction Machines

The results of a comparative experimental investigation of various media for non-invasive diagnosis of internal and external unbalanced parameters (rotor faults and unbalanced voltages) in a three-phase squirrel-cage induction machine are presented. Stator voltages, stator currents and stray flux are measured, recorded and used for computation of the current space vector, the input power and the airgap torque. The different waveforms of the stator current, current space vector, stray flux, airgap torque, partial input power and total input power are subsequently analysed using the classical fast Fourier transform (FFT)