METHODS FOR MITIGATION OF MAGNETIC FIELD GENERATED BY UNDERGROUND POWER CABLES IN POLYETHYLENE PIPES MADE OF COMPOSITE MAGNETIC MATERIAL

Abstract

The magnetic field of a high-voltage (330 kV) underground single-circuit power cable line, laid in a polyethylene pipe having magnetic properties, with the use of special loose-fill/fill-up soil of different dimensions (bulk) is studied by computer modeling. The pipe and additional soil around and near the cables are made of a composite material with effective magnetic properties and can act as a magnetic shield that reduces the level of the field on the ground. The efficiency of field shielding depending on the height and width of the composite loose-fill/fill-up soil is analyzed. The existence of the optimal not large (in height) fill-up soil for the best mitigation of the magnetic field on the ground directly above the cables, and the influence of the width of the loose-fill/fill-up soils on the shielding efficiency are revealed. The characteristic features of the magnetic field distribution within the considered shielding elements of the cable line depending on the availability or non-availability of composite loose-fill soil and the height of the fill-up soil with effective magnetic properties are presented. The shielding efficiency of underground single-circuit three-phase power cable lines when using the magnetic fill-up soil with a certain small height (volume) is grounded. References 11, figures 4.