209 / 2024-04-17 17:42:02

Impact of Shielding on the Gas-Solid Interface Charge Distribution of Real-sized DC GIS/GIL Insulator

DC GIS,surface charge accumulation,eco-friendly gas

High voltage DC gas insulated switchgear (HVDC GIS) is a crucial part of flexible DC power grid. Under the pressure of DC voltage, the surface charge accumulation of its internal basin insulators is the key problem that affects the insulation performance. The research on the surface charge accumulation characteristics of the real-sized DC GIS basin insulator and the influence mechanism of key parameters are of great significance to the development and application of DC GIS.

Based on this experimental platform, two modes of charge accumulation are proposed: "uniform charge" and "charge speckles". The accumulation of the same polarity charge is due to the homo-polarity ions movement in gas side, and the charge speckle may be caused by the impurities on the insulator surface or the defects at the triple junction. By introducing a shielding cover, the generation of charge speckles can be effectively reduced, However, on the one hand, the shield cover forms a stronger normal electric field outside the insulator under the action of DC voltage, increasing the gas side charge injection and forming a higher density of uniform charge; on the other hand, it increases the amplitude of the tangential electric field, which may lead to a decline in the insulation performance along the surface.