A Numerical Study on the Decomposition and Diffusion Characteristics of SF6 in Gas-Insulated Switchgear with Consideration of the Temperature Rising Effect

Abstract

The optimized concentration of SF6 gas is the key to maintaining a good insulation performance by GIS equipment. The precise measurements of the SF6 concentration and decomposition byproducts could be used to indicate the remaining GIS insulation level during long-term operations. In this paper, a finite-element simulation model was created to investigate the SF6 gas decomposition and diffusion dynamics. A theoretical analysis and simulation of the overheating fault, i.e., the contact between the GIS disconnect switches, were carried out, followed by an estimation of the SF6 decomposition and diffusion characteristics caused by the local heating faults, based on the calculated flow velocity field and temperature field.

Impact of Air Gap Defects on the Electrical and Mechanical Properties of a 320 kV Direct Current Gas Insulated Transmission Line Spacer

“…With its advantages of low loss, large transmission capacity, and easy grid interconnection, high voltage direct current (HVDC) transmission is steadily influencing the future direction of modern power systems [1][2][3]. A GIL spacer offers unique advantages and is thus widely used to pass through partial areas with large vertical drops and poor meteorological conditions [4][5][6]. Among the components of a GIL, the insulation spacer is indispensable for tasks such as isolating the air chamber, electrical insulation, and mechanical support [7,8].…”