Method for shielding the magnetic field generated by an electrical power transmission line and electrical power transmission line so shielded

A method for shielding the magnetic field generated by an electrical power transmission line comprising at least one electrical cable, comprising the following steps of:

• providing at least one shielding element comprised of a plurality of shielding modules arranged side by side, each shielding module made of at least one ferromagnetic material for shielding the magnetic field generated by at least one electrical cable, each of said shielding modules comprising a base and a cover, the base comprising a bottom wall and a pair of side walls, the cover comprising a main wall, and either the base comprising a pair of integral flanges extending in a predetermined direction from the end portions of the side walls or the cover comprising a pair of integral flanges extending in a predetermined direction from the end portions of the main wall;
• coupling at least one supporting element to at least one of said bases;
• laying said at least one electrical cable into said bases;
• and
• leaning said covers onto said bases so as to substantially close said shielding element.