Abstract：With the rapid development of urban power grids, the power grid has gradually evolved from a small current grounding system to a small resistance grounding system. The small resistance grounding system requires zero sequence current protection, which requires the relay protection device to act immediately to cut off the fault when a grounding fault occurs, in order to reduce the impact of grounding short-circuit current on the equipment. However, for 10 kV substations using ring busbars, the current protection principles cannot accurately distinguish the fault location when a grounding fault occurs on the busbar. This article first analyzes the operation mode of grounding transformers and the characteristics of different fault points, and verifies them through simulation experiments. Then, an improved grounding transformer protection device is proposed to achieve accurate fault location.
王宝庆, 于洋, 曹昊, 邱欢, 马彧霏. 变电站10 kV小电阻接地系统环形母线接地变压器保护功能提升[J]. 电气技术, 2025, 26(12): 58-64.
WANG Baoqing, YU Yang, CAO Hao, QIU Huan, MA Yufei. Improvement of protection function for the 10 kV small resistance grounding system ring busbar grounding transformer in substation. Electrical Engineering, 2025, 26(12): 58-64.
2025, Vol. 26 
