Development and Application of a Real-Time Monitoring and Early Warning Device for N600 Grounding Line Current in Substations Based on WAPI Network

This paper addresses the inefficiency of manual inspection and data discreteness in monitoring the N600 grounding line current of voltage transformer secondary circuits in substations. A real-time monitoring and early warning device based on the WAPI network is proposed. The device employs sensors installed on the N600 grounding line to detect current values in real time, converting them into analog current signals (4-20 mA) and wireless data via the WAPI network. Experimental results demonstrate that the device achieves high measurement accuracy, with a maximum error of only 0.13%, meeting on-site requirements. Deployed in three substations, the device has detected 17 potential grounding faults, reducing operational costs by 65%-72%, significantly enhancing the intelligence level of secondary system maintenance.