DC Link Faults Detection in a 3 phase VSI fed Induction Motor Drive using Wavelet Transform

The aim of this study is to employ the wavelet technique for the diagnosis of open-circuit and short circuit faults in the dc link of induction motor drive. The symlet wavelet is selected as the wavelet base to perform stator current analysis during faults. In this method, the stator currents are used as an input to the system. The MATLAB software is used to process discrete wavelet transform (DWT) of the signals. The stator current is used for the detection of the fault. When an open-circuit fault or a short circuit fault appears, the signal fault information is included in each frequency region. The time of the spikes in the DWT is correlated with the time of fault. As a result of time & frequency domain studies, a faulty system can be easily discriminated from the healthy system.