Neutral Voltage Analysis for Broken Rotor Bars Detection in Induction Motors Using Hilbert Transform Phase
Résumé
Most of rotor related faults in three-phase induction motors are due to broken rotor bars and end-ring defects. Nowadays, inductions motors are more frequently used with inverters which make the diagnosis process more complicated. The approach used in this paper, for the detection of a broken rotor bar in induction motor powered by a voltage fed inverter, is based on the analysis of the voltage taking place between the stator neutral and an artificial supply neutral. A comparison study with the well known Motor Current Signature Analysis (MCSA) is underlined. A theoretical analysis is investigated in order to depict all harmonic components related to the rotor defects in both line current and neutral voltage. These signatures are drawn by the phase analysis of Hilbert transform applied on the spectrum modulus of the line current and the neutral voltage. Experimental and simulation results obtained for two different induction motors confirm the aforementioned study.