Application of Electromagnetic Time Reversal Similarity Metric to Locate Partial Discharge in Transformer Winding

This paper presents a new method utilizing electromagnetic time reversal (EMTR) theory for the localization of partial discharge (PD) source inside the transformer winding by exploiting the similarity characteristics. The method comprises three main steps: (1) measure the direct time PD signal at the terminals of the winding and time-reversed it, (2) develop the winding simulation model and re-inject the time-reversed signal in it, (3) guess the various PD locations and compute the PD current signal for that, then determine the similarity metric between re-injected PD signal and PD current signals for various guessed locations to get the actual PD location. The similarity metric is obtained by employing the cross-correlation between the re-injected PD signal and PD current signals calculated for different GPDLs in reversed time. The maximum value of cross-correlated signals provides the actual PD location in the winding. The performance of the proposed method is verified through a simulation study.