Analysis of non-contact measurement methods for sag of overhead transmission lines

Amidst the global integration of renewable energy sources to combat the energy crisis and foster low-carbon power systems, expanding power transmission lines becomes imperative, significantly elevating operational risks. This paper addresses the crucial concern of sag in power lines and explores non-contact measurement methods for sag through advanced magnetoresistive materials, focusing on spatial magnetic field characteristics. Three reference lines—tower longitudinal line, projection line, and center perpendicular line—are investigated through finite element simulations. The results provide valuable insights by suggesting optimal locations for sensor placement, delineating linear correlations between magnetic field intensity and sag values, and presenting a novel sag measurement method by finding the maximum magnetic field strength point in the Z-axis component. These results contribute to efficient and cost-effective sag monitoring in overhead transmission lines, which is crucial for enhancing the safety and reliability of power systems amid renewable energy integration.