Numerical Study on Temperature Rise and Insulation Characteristics of Opening Busbar Applied to Large Capacity GIS

In order to alleviate the contradiction between steady state temperature rise control and compact design of GIS (Gas Insulated Switchgear), this paper establishes a two-dimensional electromagnetic-fluid-thermal full-coupling simulation model, and analyzes the temperature rise and insulating performance of GIS under the traditional round-tube shaped busbar and open busbar structure. The results show that: with the openings on the traditional round tube busbar, the high temperature gas inside the tube exchanges heat with the low temperature gas outside, and the natural convection heat transfer inside the GIS is significantly strengthened; when the number of openings is two, three and four, the maximum steady-state temperature rise is reduced by 11%, 13% and 8%, respectively; the openings have a small effect on the internal electric field; the maximum electric field strength is increased by 5%, and the reduction in the steady-state temperature value of the GIS makes it possible to reduce the temperature rise of the insulating gas and the insulation performance. The reduction of steady state temperature value inside GIS makes the critical breakdown field strength of insulating gas increase, and the insulation performance is good at this time. The research in this paper provides some guidance for the design of large-capacity GIS.