Locating partial discharge in power transformer by electrical method

To locale partial discharge (PD) source in power transformer by electrical method, the propagating principle of PD pulse along transformer windings and the response of PD pulse at detecting terminals outside the transformer are studied. Simulating analysis through numerical model and imitating experiment on transformer winding are carried out. A simulation model of transformer winding is established. The equivalent circuit is made-up in order that the transfer property of PD pulse along the winding could be calculated and analyzed. There are differences in the properties according to the PD source positions so that the relationship between the difference and PD positions can provide some information for PD locating. Based on numerical treatment of the relationship, the electrical method of PD locating is presented. The energy of the measured signal is used to locale PD source. The device for PD pulse imitating is developed for the experiments on transformer windings. The terminal signals caused by PDs at different positions are measured during the experiments, and the results indicate that the locating accuracy of these methods is satisfied for engineering practice use.