Detection of broken rotor bars in induction motors using wavelet analysis

In this paper a new method for the detection of broken rotor bars in induction machines is introduced. The startup transient current of an induction machine is used as the medium for diagnoses. The fundamental component is extracted using an algorithm that predicts the instantaneous amplitude and frequency during startup. The residual current is then analyzed using wavelets and a comparison is made between a healthy and damaged machine. This method of machine condition monitoring is not load dependant and can be used for machines that are unloaded.