Overhead High-Voltage Transmission-Line Current Monitoring by Magnetoresistive Sensors and Current Source Reconstruction at Transmission Tower

This paper proposes a novel current monitoring technology based on magnetic field sensing at a transmission tower for overhead high-voltage transmission lines (HVTLs), which can accurately measure phase current parameters in real time. This technology is based on the phenomenon that the magnetic field distribution at the top level of a transmission tower can reflect the operation states of the transmission lines including current amplitude and phase angle imbalances. A current source reconstruction method based on stochastic optimization strategy was developed to reconstruct the electrical parameters from the magnetic field emanated by the overhead transmission lines. This concept of current monitoring by magnetic field sensing and current source reconstruction was experimentally implemented and verified in our laboratory setup. A typical model of 500 kV three-phase transmission lines was simulated to further corroborate this technology. The reconstruction results for the 500 kV transmission lines verify the feasibility and practicality of this novel current monitoring technology based on magnetic field sensing at the top of a transmission tower for monitoring overhead transmission lines.