An Experimental Validation of Electromagnetic Time Reversal Technique for Localization of Partial Discharge Inside Transformer Winding

This article presents an electromagnetic time reversal (EMTR)-based innovative technique for the localization of partial discharge (PD) inside the transformer winding. The technique involves the measurement of PD signals from the line and neutral-end terminals of the transformer winding. Then, a ladder-network-based winding model is constructed by time reversal of the measured PD signals and back-injecting the time-reversed PD signals into the model. Thereafter, the energy of the PD current signal is computed by short-circuiting the capacitance at various locations in the winding model. The winding location, associated with the highest energy concentration, indicates the actual PD location. The suggested technique is experimentally validated using the layer type winding model (LTWM), disk type winding model (DTWM), and actual 11 kV high voltage winding model (HVWM) with a rectangular pulse signal generated by a function generator, a real PD signal generated by the point-sphere electrode, and the PD signal generated by the PD calibrator, respectively. The results affirm the accuracy and effectiveness of the suggested technique to locate the PD source inside transformer windings. Finally, a comparative analysis of the proposed technique against various established techniques confirms its practical applicability for the localization of PD within the winding structure of the transformer.