Partial discharge locating in power transformer using wavelet transform of bushing and grounded neutral currents

IEEE standard has been specified Almost 30.6% of total faults in power transformer are electrical failures. Exact location of Partial Discharges (PD) is of a major concern. Therefore, techniques for locating the PD sources are very important in both the maintenance and repair a transformer. A new technique is proposed for partial discharge locating and pulse propagation of PDs. The proposed method is based on wavelet and that is the injection of the PD current source in various nodes of an identified model and then measurement of the current in bushing and grounded neutral separately. By applying a specific wavelet transform and also statistic mathematic methods into measured currents, some criterions are achieved for the accurate location of PDs.