Development of a Partial Discharge Measuring Method for a Long-Distance Cable Line

The authors have been developing a new measurement method for measuring partial discharge (PD) in a long-distance cable line using a capacitive coupling method. This method proposes that a PD signal can be detected by a newly proposed capacitive coupling electrode between the shielding layer and an additional aluminum foil. In this article, first, the theoretical background of the proposed method was described including the generation, propagation, and detection of the PD signal. Second, the proposed method was applied to observe PD activity in an RG58A/U communication cable and a numerical simulation was also performed in the same manner as the measurement system. It was confirmed that the PD signal was successfully detected. Third, the feasibility of the proposed method for applying in a full-size 6.6 kV XLPE, (Hitachi Cable Ltd., Hitachi Magnet Wire Corp., Tokyo, Japan) cable line was investigated. It was revealed that the proposed method can be applied for a full-size cable. Finally, an attempt was made to understand the effect of the coupling capacitor on the detection intensity. Also, the detection limit of the proposed method based on the noise level was analyzed. It was revealed that the detection sensitivity was finally determined as 400 pC, which was the detection limit. (c) 2019 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.