ABB, the power and automation technology group, says it has achieved a significant breakthrough in gas insulated switchgear technology with the development of a solution that deploys a new insulation gas mixture as a substitute for sulphur hexafluoride (SF6. The new technology will be deployed for the first time at a substation located in Oerlikon, Zürich, as a pilot installation for the leading Swiss utility, ewz. In addition to the 170 kV high voltage GIS, ABB will also install medium voltage GIS with the new gas mixture.
This alternate product has similar insulation properties to the SF6 gas now used in switchgear, but has a substantially lower environmental impact owing to its extremely low global warming potential. ABB’s gas-insulated switchgear with the new gas has the potential to lower carbon dioxide equivalent emissions by up to 50 % through the lifecycle of the equipment, compared to its predecessor with the same rating.
"This is a significant achievement and can pave the way for more eco-efficient switchgear in the years ahead," said Bernhard Jucker, head of ABB’s Power Products division.
SF6 gas is been used extensively in the electrical industry for dielectric insulation and current interruption owing to its physical properties. Pressurised SF6 gas aids the safe and reliable operation of gas-insulated switchgear because it has a much higher dielectric strength than other insulation media, making it possible to significantly reduce the size of switchgear installations without the danger of arcing and enabling installation in areas where space is at a premium. However, SF6 is a known greenhouse gas and its lifecycle management requires careful handling for utility and industrial users. The cost of managing it in a compliant manner can also be substantial, particularly when decommissioning aging substations.
ABB pioneered high-voltage GIS in the mid-1960s. It now has a global installed base of more than 23 000 bays. The latest breakthrough is said to enable further reductions in carbon emissions without compromising efficiency and reliability.
