On-Line Partial Discharge Localization in Power Cables Based on Electromagnetic Time Reversal Theory - Numerical Validation

This paper presents the numerical validation of a new on-line location method of partial discharge (PD) in cables of Medium Voltage (MV) power networks based on the electromagnetic time reversal (EMTR) theory. Because PD events are a symptom of cable insulation degradation, PDs localization is a key topic for fault prevention on power networks, increasing their reliability and resilience and to guaranteeing electricity security. A description of the proposed EMTR PD location method is given and its effectiveness and accuracy are analyzed in lines with both homogeneous and inhomogeneous power cables. The accuracy of PD location methods is strongly affected by the distortion of the PD pulses during their propagation on power lines, caused mainly by the skin effect. For this reason, the accuracy of the proposed location method is analyzed using a lossy model of power networks that is able to reproduce PD signals distortion. The model used, realized using the transmission line matrix (TLM) method, is also presented here and theoretically validated.