Development of On-Line Partial Discharge Locator for Electric Power Cable

Although the demand of reliable power systems and stability of supplying electric power are quite crucial for all of power companies, aging and deterioration of the electric power equipment are ongoing. For this reason, we propose a partial discharge locator (PDL) system. This is possible to locate the cable fault for power cables under the transmission and the distribution systems in operation. In conventional systems, the propagation velocity of a PD pulse must be known for the cable fault detection. However, it likely depends on the deterioration state of the power cable. Thus, PDL uses injection signals only to measure the propagating time instead of obtaining propagation velocity. This implicates the need of communication among two devices in order to make system accurate. In this paper, we first show how the PDL works on-line power cable with time synchronization between two sides and injection trigger for obtaining propagating time. We also provide information of the propagation characteristics of a current pulse which simulates a partial discharge current on branched 22kV XLPE cables.