Design and Application of Grounding Circulation Current Monitoring System for High-Voltage Single-Core Cables

With the expansion of power systems, high-voltage single-core cables are widely used in transmission networks due to their structural advantages. However, abnormal grounding circulation currents in the cable metal shielding layer may cause local overheating, insulation aging, and even breakdown risks. This paper takes 35 kV and 10 kV single-core cables in a factory area as the research object, designing a real-time grounding circulation current monitoring system based on the NARI monitoring platform. The system integrates high-precision current transformers (LMZJ1-0.5) and measurement/control devices (PCS-9705TE), combined with communication switches and telecontrol units (PCS-9799), to achieve centralized monitoring, over-limit alarms, and remote data transmission for multi-circuit cable grounding circulation currents. Practical applications demonstrate that the system effectively identifies abnormal grounding currents, improves cable operational safety, reduces unplanned outage risks, and provides technical support for the intelligent operation and maintenance of power systems.