Current-sensing-array-based dielectric health monitoring system for secondary power circuits

The secondary power system plays a crucial role in ensuring reliable power supply and safe production of the power system. The system consists of secondary equipment and secondary circuits, where the integrity of the secondary circuits and the correctness of wiring are crucial for the regular operation of protection and automation devices. If there are problems with the secondary circuit, especially wiring errors, it will directly affect the response of relay protection and automation devices, which may lead to system failures or accidents. In the actual operation of substations, multiple grounding points on the secondary sides of PT (voltage transformer) and current transformer (CT) often occur, which may cause misoperation or the refusal of relay protection devices, significantly increasing the risk of system operation. To address this issue, this paper proposes an online monitoring system based on a distributed zero-sequence current monitoring method for real-time monitoring of the insulation status of secondary AC circuits. This system effectively reduces the workload of operation and maintenance personnel, improves operational and maintenance efficiency and monitoring accuracy, thereby ensuring the reliable operation of the substation's secondary circuit and providing strong guarantees for the stability and safety of the power system.