Induction motor broken bar detection for a thermal power-plant application. A case study

Abstract

The paper presents a case study results emoting detection for a broken bar in an induction motor thermal power-plant. Two identical 3.15 MW motors are analyzed. The malfunctioning motor suffers from increased vibrations. A fault on the rotor is suspected. The induction motor phase current is analyzed for the healthy and the malfunctioning motor. The feature extraction is based on transient and steady state analysis. The Fourier, Hilbert and Wavelet transforms are used. Because of the operational setting shaft-load is low. It is shown that a broken bar of a high-voltage high-power induction motor can be reliable detected by using state-of-the-arte digital signal processing techniques.