Partial discharge location in power transformers using the spectra of the terminal current signals

Partial discharges (PDs) are a major source of insulation failure in a power transformer. The accurate location of the discharge is of crucial importance in on-site maintenance and repair. For power transformers operating at 132 kV and below and having a continuous disc type winding construction, a novel approach for PD location, based on a study of how PDs propagate in a transformer winding, is presented. Experimental tests are used to show that the PD source can be located using information available in the current signals measured at the transformer terminals