CAD investigation of voltage potential and electrical field distribution on 36 kV load break switch

The paper deals with the investigation of the electrical field distribution on an actual 36 kV gas insulated three phase load break switch application by a CAD analysis. The proposed medium voltage switch characteristics and applications are described. In particular the switchgear characteristics and its performances are focused. An accurate static analysis of the electrical field distribution in both the switchgear and the stainless steel tank will be carried out by several simulations on a suitable model through a finite element method (FEM). The numerical analysis is applied with two and three dimensional dedicated software tools. The simulation results allow the correct design of the distances for both the fixed and the rotating electrical contacts. The information on the electrical field distribution allows the correct fitting of the distances of the electrical contact and the pressure value of the insulation gas (SF₆) injected in both the switchgear and the stainless steel tank.