Effect of contact area and the number of parallel insulators on the flashover voltage in compressed gases

Solid insulators (spacers) have been used as physical support of high voltage conductors in compressed gas insulated system (GIS) [1-2]. The design of an insulation system often requires multiple spacers in parallel. As the number of spacers increases, the possibility of the presence of weak points increases, and the probability of an electrical breakdown of the system increases [3]. It is important to study the influence of the number of parallel insulators on the breakdown voltage of the system. There is insufficient data on the effect of the surface flashover of varying the insulator diameter and the number of parallel insulators in high pressures of SF6 and N2. The dependence of the flashover on the contact area of the spacer is required in the design of insulating systems. This is because as the spacer area is varied, the capacitance and therefore the energy stored in the gap which affects the dielectric strength of the insulation is also varied.