The Effect of Variation Resistance Broken Bars in Induction Motor Using Stator Current Signature Analysis

Abstract

In all mechanical devices, motors are subject to failures, which can sometimes lead to the shutting down of an entire industrial process. That is the reason why predictive maintenance and prognosis are necessary. Motor current signature analysis is a condition monitoring technique that is now widely used to diagnose problems such as broken rotor bars, abnormal levels of airgap eccentricity, shorted turns in low voltage stator windings and some mechanical problems. This paper presents the effect of the broken bar time evolution since the created incipient fault on the various characteristics of the induction machine such as torque, speed and currents. The induction motor is simulated while the rotor bar resistance is varying linearly versus time since its normal value to the final broken bar situation (partial to total broken bar). The methods used for analysis are based on: · the Lissajous representation of Park vector current components · spectral analysis of stator current and the modulus of Park vector current By this way, we can observe the incipient fault impact on the different characteristics of the machines such as torque, speed and currents.