261 / 2018-09-24 23:18:34

Investigation on the Spacer Flashover in Humid SF6 under Different Electrical Stresses

Gas Insulated Switchgear,GIS,flashover characteristics,Humid SF6,Humidity,breakdown strength,Spacer insulator

Humidity has been suspected to be involved in insulation failures of Gas Insulated Switchgear (GIS) in our case study consisting of 631 CB-bays of GIS located in Java and Bali. From this finding, laboratory tests have been conducted to find the influence of humidity to the breakdown strength, particularly on the GIS spacer.
Setups have been developed in the HV Laboratory of TU Delft. The model consists of a spacer and humid SF6. The controlled parameters are the humidity and the gas pressure, while the temperature is constant at 20oC.
Tests have been conducted under electrical stresses of AC, Lightning Impulse (LI) + and -, and Switching Impulse (SI). The humidity has been adjusted with dry, humid, saturation, and wet conditions. As a conclusion, the humidity does not influence on the breakdown strength of the spacer as long as there is no condensation.