Time constant evaluation of transient AC – DC field distribution

This paper focuses on the time constant of transient AC – DC field distribution of DC GIS. As the resistive field depends on the conductivity of solid insulation and surrounding gas in the GIS, these parameters need to be assessed. Therefore, the physics of nonlinear conduction in the gas is considered as a result of natural charge generation by radiation and recombination. The time constant of the system is then evaluated using a simulation model that takes into account a gas model and the surface and bulk conductivities of solid insulator. The influence of different parameters, such as the nonlinear conductivity, the shape and dimensions of the solid insulator, are then investigated. Variations of the surface and bulk conductivity of solid insulator with dependency on the electrical…