An Operation State Detection Method of DC Grounding Electrodes Based on Surface Potential Distribution

During the long-term operation of the DC grounding electrode of the converter station, there are often hazards such as heating and aging of the coke layer, and burning and corrosion at the connection between the feed rod and the cable, resulting in break problems at the connection between the cable and the feed rod. Currently, the operational status monitoring of grounding electrodes primarily relies on daily tracking of well temperature, humidity, and water level characteristics; periodic testing; and on-site excavation. However, the above methods cannot accurately obtain the breakage location information at the connection between the cable and the feed rod. To address these issues, this paper first analyzes the current distribution law in the feeder rod of the DC grounding electrode. Subsequently, it studies the impact of localized fractures in the DC grounding electrode on the surface potential distribution characteristics. Finally, an Operation State Detection Method (OSDM) based on potential distribution is proposed and validated through case studies, demonstrating high measurement accuracy. The results indicate that OSDM can effectively monitor the operational status of DC grounding electrodes, providing a reference for their maintenance and repair.