On-line partial discharge diagnostic system in power cable system

An online partial discharge diagnostic system is presented in this paper. The system is capable of detecting a PD event in a power cable system as low as 1 pC. Coupling to the system is made through special sensors that utilize inductive and capacitive coupling. These sensors have a detection bandwidth of 100 kHz to up to 300 MHz. The online PD system indicates location of the insulation anomaly both longitudinally and radially in a cable. Furthermore, the system is applicable to both laminar (PILC) and extruded (PE, XLPE, EPR) cables.