Skin effect and proximity effect in a real, high voltage, double three-phase system

Both skin effect and proximity effect increase losses in any conductor with time varying current. In order to determine those extra losses in a real case of two three-phase systems, buried together in a ground, the electromagnetic field inside the cables and in vicinity was calculated for four different frequencies. This paper shows the investigation of a current distribution in all conducting cables´ parts, which gives the best insight into skin and proximity effects significance. Moreover, magnetic field outside the system, important for electromagnetic induction in neighboring berried metal elements, such as water and gas pipes, was calculated as well. All calculations were carried out applying COMSOL Multiphysics 3.5a computer program. The calculation results are done for the concrete double 3-phase system, as a combination of 6 single-core cables XHE-49-A, 64/110kV, with the cross-section 1×1000/95mm2, graphically, together with comments.