A study on proximity effect of current distribution in conductors and improvement of GIS arrangement

Proximity effect is a phenomenon such that an electric current density distribution becomes asymmetric when an alternating current flows in conductors arranged at a short distance. This effect possibly raises problems in the case when cylindrical conductors are arranged at a highly short distance like in compact and large capacity GIS. For example, unexpected local concentration of an electric current may cause welding or arcing especially in contact joint areas. Therefore, detailed study on the proximity effect is important. In this paper, it is shown that this effect can be quantitatively evaluated with an experiment and two kind of computations, finite element method and approximated lumped parameter circuit. Finally, ideas for improvement of GIS arrangement are suggested.