The pioneering technology leader ABB, has been working closely with Dutch utility Liander to gain field experience with SF6-free gas-insulated switchgear. In extensive field tests, the SafeRing AirPlus ring main units (RMU) with the innovative AirPlus™ insulation gas have proven so far to be as reliable and behave exactly as expected.
Liander, a company within the Alliander Group, is the largest utility company in the Netherlands. They distribute electricity and gas to about three million customers. Liander has sustainability high on the agenda and they actively encourage the development of sustainable grid solutions. The company was looking for 20kV ring main units (RMU) that were more compact than those available with the commonly used air-insulated technology. Yet, to meet the goal of a sustainable grid solution, they sought an alternative to the potent greenhouse gas SF6, the usual insulation medium used in compact gas-insulated switchgear (GIS).
ABB’s ground-breaking AirPlus technology provided a perfect match with the SafeRing AirPlus, a gas-insulated SF6 -free RMU. The RMU maintains the same compact dimensions as existing SF6-filled switchgear, which brings optimal use of space and reduces the global warming potential by 99.99 percent compared to SF6. The SafeRing AirPlus units use vacuum technology for switching, so the gas is only used for insulation.
Liander and ABB teamed up to launch a pilot project with SafeRing AirPlus in Liander’s medium-voltage grid. The four pilot units were installed in compact secondary substations and taken into operation in November of 2015 at wind farms in Liander’s grid in Flevoland, the Netherlands. The pilot project will run for three years and the results so far, which have been gathered over 18 months, have been excellent. The operational performance and gas samples taken indicate that the units behave exactly as expected. The pilot project and its initial findings are a success: the eco-efficient AirPlus insulation gas is an important step forward towards sustainable and climate-friendly grid solutions.
“We are very excited about the highly encouraging results from this pilot project” said Bruno Melles, managing director of ABB’s Medium Voltage business. Our ground-breaking eco-efficient technology is reliable and used as an insulation medium in our existing proven switchgear portfolio. This collaboration with Liander is providing valuable data on our innovative technology and the AirPlus insulation gas, and is reaffirming ABB’s position as a trusted partner for climate-friendly and reliable solutions.”
SafeRing AirPlus was launched last year and is the first 24 kV medium-voltage RMU with an alternative to SF6 on the market. The RMU makes use of AirPlus, a new fluoroketone-based gas mixture developed by ABB in collaboration with 3M. The new gas has a global warming potential (GWP) of less than one - almost 100 percent lower than SF6.
ABB offers gas-insulated and air-insulated switchgear for the distribution of electrical energy, both for primary and secondary distribution. On the secondary level, RMUs are often installed in compact substations or small distribution substations to ensure a safe uninterrupted power supply to households and small industries. The compact dimensions also meet the space requirements often encountered in industrial and power plant applications, as well as mining and marine industries. In the transport and infrastructure segment, secondary distribution switchgear feed traction power supplies or public buildings such as hospitals, airports and railway stations.
ABB provides utility, and industrial and commercial customers with safe, reliable and smart technologies for the distribution of electricity. The extensive global offering includes distribution automation products, switching, limiting, measuring and sensing devices, switchgear, modular substation packages and related services.