Mitigation of magnetic fields in overhead power lines through genetic algorithm-based electromechanical compensation

Abstract

The magnetic fields generated by overhead high-voltage transmission lines have attracted significant attention owing to their potential health risks. Various techniques have been developed to mitigate these fields, which are influenced by both the current flow and geometric configuration of overhead transmission lines (OHTLs). Mitigation strategies include electrical compensation, which adjusts the phase currents within permissible limits, and mechanical rearrangement, which optimizes the conductor placement under specific constraints. This study proposes an advanced approach that integrates electrical compensation optimized using a genetic algorithm (GA) with the mechanical reconfiguration of OHTLs. The electrical compensation is implemented by inserting a combination of reactive series and shunt elements in each phase, creating an imbalance in current. Passive series and shunt elements were optimized to achieve optimal electrical compensation. The GA is an evolutionary optimization method that provides more than one solution and does not require complex modeling, as in traditional optimization methods. The GA considers conductor positions and passive reactive elements as genes, with magnetic field minimization as the fitness function. The results show that passive-reactive compensation has a less significant effect on magnetic field mitigation than mechanical rearrangement because the current control is not continuous and is limited by the reactive elements. However, the lowest possible magnetic field levels are achieved when electrical compensation is combined with mechanical compensation. In the present study, two cases were tested using the proposed method. The results show that electrical compensation improves the mechanical rearrangement method by approximately 29% in Case 1 and 70% in Case 2.