SF

6

has long been used as the main arc interruption and insulating medium for GIS switchgear in high voltage power transmission and transformation equipment. Although SF

6

has such advantage as extremely stable chemical properties

yet the disadvantage that excessive emissions will cause global warming shall not be ignored. Because of this

scholars both at home and abroad continue to carry out in-depth research and test on its alternative gases. In this paper

the clean air is used as insulation gas to optimize the de

sign of 126 kV environmentally friendly GIS insulating spacer. The existing 126 kV SF

6

GIS insulating spacer structure is taken as the base

such key dimensions as conductor center distance

φD

gap distance

H

between the conductor and enclosure

radius

R

of the grounding shield ring and the insulating spacer thickness

T

are optimized by using control variable method. The better scheme of insulating spacer meeting the insulation strength of clean air is finally determined through a large number of simulation calculation and comparison analysis. At the same time

the insulation and mechanical performance of the insulating spacer is verified further by test

which strongly supports its structure rationality. The method provides a feasible solution for the design of clean air insulated insulating spacer.