Summary of Grounding Fault Finding Strategies in Substation DC System

[Introduction] With the rapid development of power electronic equipment and artificial intelligence and other high-tech, DC (Direct Current) system has been popularized and applied in substations. The grounding fault of the substation DC system has become an important factor affecting the safe and stable operation of the substation. [Method] Firstly, the DC system of the substation was introduced, and its components, typical types of DC ground faults and their adverse effects were analyzed. Then, the principle of five common DC ground fault finding strategies was emphasized. [Result] Based on their respective research status and application scenarios, the advantages and disadvantages of various finding strategy are compared and analyzed. [Conclusion] Combined with the existing problems and technical development trends, the future research directions of DC grounding fault detection at home and abroad are prospected from the perspectives of accurate fault location, complex fault identification, finding accuracy and the improvement of the endurance of portable insulation detection device.