Disk to disk fault diagnosis during impulse testing by using wavelet transform

A disk to disk breakdown during impulse test in power transformer is usually because of failure in winding insulations, these faults can cause substantial damage if they are not detected and isolated promptly, different methods and models have been developed to detect faults in transformer windings by recording waveforms from voltages and neutral current but the drawback of these methods is the representation of the fault as a short circuit with constant conductance, but here the arc is modeled to have more realistic characteristic of a fault. Wavelet transform is used to discriminate between two non-stationary signals such as constant conductance fault or a disk to disk arcing fault and then a technique that estimates the location of the arcing faults between two disks is presented in this paper.