66 kV-20 MVA Gas insulated Transformer Using Natural Origin Gas (N₂) with Reduced Environmental Load and Improved Maintainability

This paper reports on the development of a 66 kV-20 MVA gas-insulated transformer that uses nitrogen (N₂), a natural origin gas, with the aim of reducing the environmental impact of conventional SF₆ gas-insulated transformers. N2 offers excellent environmental characteristics, including high safety and a global warming potential (GWP) of zero. However, its cooling and insulating performance at the same gas pressure is about one-third of that of sulfur hexafluoride