Detection and Location of Partial Discharges in Transformers Based on High Frequency Winding Responses

Localized breakdowns in transformer windings insulation, known as partial discharges (PD), produce electrical transients which propagate through the windings to the terminals. By analyzing the electrical signals measured at the terminals, one is able to estimate the location of the fault and the discharge magnitude. The winding frequency response characteristics influence the PD signals as measured at the terminals. This work is focused on the high frequency range from about tens of kHz to a few MHz and discussed the application of various high-frequency winding models: capacitive ladder network, single transmission line, and multi-conductor transmission line in solving the problem.