Analysis Of Induction Motor With Broken Rotor Bars Using Discrete Wavelet Transform
This paper presents the analysis of startup transient current signals of squirrel cage induction motor with broken rotor bars using Wavelet Transform (WT). At light load there occurs a difficulty to distinguish a faulty rotor with a healthy rotor. Since the length of the startup transient is only a few cycles depending on the load, all the information regarding the machine's condition will be present within this transient. Because the Fourier Transform is integrating over infinity, all the information that exists during the start up transient will be lost. This poses the problem that the Fourier Transform cannot be used. The Wavelet Transform is used to analyze the start up transient. Also the wavelet technique helps to provide additional information about its transient characteristics which cannot be detected using Fast Fourier Transform (FFT). Finally, the resulting wavelet coefficients are then compared with different degrees of broken rotor.