Enhancing the efficiency and lifespan of high-voltage systems through precise SF6 measurement

Sulphur hexafluoride (SF₆), a colourless and odourless gas composed of sulphur and six fluorine atoms, plays a crucial role in the electrical industry. SF₆ exhibits an electrical insulating capability approximately three times higher than that of air, making it a premier insulating and switching gas in medium and high-voltage applications.

In high-voltage systems and switchgear, SF₆ serves to prevent short circuits and arcs while enhancing efficiency. Pure SF₆ is the standard filling in gas-insulated switchgear (GIS). However, over time, gas chambers become contaminated with water vapour (H2O) due to permeation and desorption from internal materials.

Although water vapour and SF₆ do not typically react with each other, in the presence of high-energy discharges, hydrogen and oxygen dissociate from water vapour and react with sulphur and fluorine from SF₆, leading to the formation of decomposition by-products. These include sulphur dioxide (SO2) and hydrofluoric acid (HF), which can corrode the internal components of gas chambers. Using SF₆ with low water vapour content (low humidity) is critical to minimise the risk of forming these corrosive compounds.

Process Insights has developed technology to perform precise monitoring of humidity, SF₆ purity, and SO2 concentration in SF₆-insulated switchgear (GIS) and other high-voltage equipment. The MBW CALIBRATION MODEL 973-SF₆ is an advanced SF6 gas analyser that provides a high-quality and environmentally friendly measurement solution within a single self-contained unit.

This innovation delivers accurate measurement data, contributing to the preventive maintenance of GIS systems. This technology allows operators to maximise the efficiency and lifespan of their high-voltage systems while minimising environmental impact.