High Voltage Gaseous Insulation

Today, sulfur hexafluoride (SF₆) is used in high-voltage gas insulated equipment (GIS) in electric power transmission and distribution systems. It combines a high electric strength and a low boiling point, with long-term chemical stability and easy handling. However, since SF6 is one of the most potent greenhouse gases (global warming potential 23’500), several attempts have been made to find alternative insulation gases and gas mixtures.

Our group's research investigates novel molecular gases with low global warming potential for application in high voltage insulation as gas mixtures. Research methods are experimental (from Pulsed Townsend Experiments to determine swarm parameters to breakdown experiments to determine practical insulation strengths) and numerical (from quantum chemical simulations to determine kinetic reaction networks to 1D stepped leader breakdowns to predict breakdown strengths)

Partnership: ABB Schweiz AG, GE Vernova, Hitachi Energy,  Siemens AG (Corporate Technology), SINTEF, NTNU Trondheim

Researchers: Hanut Vemulapalli, Austin Eichelberg, Hans-Christoph Töpper and Mücahid Akbas

Gaseous detectors in high-energy physics experiments are today also operated with gas mixtures containing compounds with high global warming potential, such as R134a and SF₆. Environmentally friendly alternative gas mixtures that can be used in today's equipment are thus the topic of current research.

Our group's contribution to the field is on the one hand the determination of basic molecular cross sections of novel alternative gases and on the other hand a detailed simulation environment of the detector performance to systematically search for new (optimal) gas mixtures.

Partnership: CERN

Researchers: Marnik Metting van Rijn and Dario Stocco