Development of Medium-voltage Switchgear for Reducing Environmental Impact and Space-saving

Kenji Tsuchiya Koichi Nagano Ayumu Morita Tetsuya Hirao OVERVIEW: To make medium-voltage switchgear (52 kV or less) smaller and more robust, there has been a shift away from AISs and toward GISs that use SF6 gas . However, the high global warming coefficient of SF6 gas means it was designated as a greenhouse gas by the Kyoto Protocol (Kyoto Protocol to the United Nations Framework Convention on Climate Change) adopted at the Third Session of the Conference of the Parties to the United Nations Framework Convention on Climate Change held in Kyoto in December 1997. Responding to this, Hitachi quickly embarked on the development of medium-voltage switchgear with the aim of eliminating use of SF6 gas.