Reducing the Magnetic Field Level of Single-Circuit Overhead Power Lines in Multi-Storey Buildings by Means of Active and Passive Shielding

Abstract

The purpose of the work is a theoretical and experimental study of the effectiveness of combined shielding, including active and passive shielding using a continuous screen, of the magnetic field generated by single-circuit power lines with a triangular arrangement of wires inside multi-storey buildings. To achieve this goal, the structure of the combined screen has been determined, which consists of a double-circuit active and a U-shaped solid passive part and is characterized by increased efficiency in reducing the level of the industrial frequency magnetic field. Designing a combined screen comes down to solving a minimax vector optimization problem, in which the vector objective function is calculated based on solutions to Maxwell's equations in a quasi-stationary approximation using the COMSOL Multiphysics software package. The most important results are the values of the coordinates of the spatial location of two compensation windings, the magnitude of currents and their phases in these windings of the active shielding system, as well as the parameters of the U-shaped continuous passive screen, which made it possible to increase the efficiency of shielding the magnetic field generated by single-circuit lines, calculated during the design of the combined screen. Power transmission with a triangular arrangement of wires inside multi-storey buildings. The significance of the results obtained is that practical recommendations are given for the reasonable choice of the spatial arrangement of two shielding windings of a robust active shielding system and the parameters of a Ushaped continuous passive shield of combined shielding of the magnetic field generated by singlecircuit overhead power lines inside multi-storey buildings.