Identification of multiple partial discharge sources in high voltage transformer windings

Partial discharge (PD) analysis is an important tool for assessing the lifespan of power equipment especially in cables and high voltage (HV) transformers. Different PD sources have different effects on the condition and performance of power equipment insulation system. Therefore, the ability to identify different PD sources is a great interest for both system utilities and equipment manufacturers. Hence, an experiment has been designed at the Tony Davies High Voltage Laboratory, University of Southampton to access the methodologies for the identification of multiple PD sources within a HV transformer windings. Previous work at Southampton developed a non-linear based technique that facilitates identification of the location of a PD source within an interleaved winding. This project is concerned with the feasibility of locating several sources simultaneously based only on measurement data from wideband RFCTs placed at the neutral to earth point and the bushing tap-point to earth. Initial results from a simple experiment are presented and development of an analytical approach described.