Noncontact Operation-State Monitoring Technology Based on Magnetic-Field Sensing for Overhead High-Voltage Transmission Lines

This paper proposed a novel noncontact technology of operation-state monitoring based on magnetic-field sensing for high-voltage transmission lines, which can simultaneously measure both electrical and spatial parameters in real time. This technology was derived from research on the magnetic-field distribution at the ground level when the transmission lines operate in different states, including sagging, galloping, and current imbalance. Two typical models of high-voltage three-phase transmission lines were simulated, and the resulting magnetic fields were calculated. The correlation between the magnetic-field variations and the operation states were analyzed. Based on such correlation, a source reconstruction method was developed to reconstruct the spatial and electrical parameters from the magnetic field emanated by the overhead transmission lines. The reconstruction results for the 500-kV and 220-kV transmission lines verify the feasibility and practicality of this novel noncontact transmission-line monitoring technology based on magnetic-field sensing.