Coil Antenna Sensor-Based Measurement Method to Online Detect Partial Discharge in Distributed Power Networks

Partial discharge (PD) is a prevalent sign of insulation aging and defects in high-voltage power equipment. Extended PD can lead to ongoing physical and chemical reactions, resulting in accelerated insulation damage and eventual equipment failure. To early detect PD, this article proposes a novel wideband high-frequency coil antenna sensor-based measurement method. It maintains a liftoff distance from the conducting ground wire without the need for clamping, unlike the typical high-frequency current transformer (HFCT) sensor. The coil antenna sensor is designed with a multimode resonant ladder structure and measured with a broad impedance bandwidth. The in-lab experiment is conducted in an anechoic chamber. Subsequently, a systematic experimental setup is established with the antenna sensor for the field trial. The front end is situated in the transform and switchgear substations, while the collected data are transmitted via the Internet network to the back end for convenient monitoring. The phase-resolved PD (PRPD) pattern is clearly discernible. The test results demonstrate the feasibility of the proposed measurement method, affirming the efficiency of the designed coil antenna sensor along with its supporting system in PD detection.