Development of a partial discharge detection algorithm and verification test for extra-high-voltage cable system

Even though a lot of research has been devoted to find partial discharge (PD) sources based on the time difference of pulses, it has been reported that studies have been unable to obtain precise locations in joints due to the errors caused by the attenuation or distortion of PD pulses. In this study, in order to reduce the issues, 'Precise PD finding' is developed to obtain the accurate locations of PD sources by considering not only the time difference of pulses, but also pulse polarity. Accordingly, a PD detection algorithm is implemented. An attachable inductive sensor is designed and fabricated and then applied to a real scaled 154 kV XLPE cable with a joint. From the experimental results, the algorithm was verified to successfully find the locations of PD sources. The algorithm was then applied to an on-site, 345 kV XLPE cable. Consequently, PD sources were detected in a normal straight joint box and confirmed through a disassembly investigation.