Development and Implementation of Gas-Insulated Metal-Enclosed Switchgear With Breaking Capability of 63 kA for 1 100 kV AC Power Transmission Project

The gas-insulated metal-enclosed switchgear (GIS) is the most important control and protection equipment in 1 100 kV power grid and it plays important role of ensuring secure and stable operation and reliable power supply of UHVAC power grid. In view of the fact that GIS with breaking capability of 50 kA for 1 100 kV pilot power transmission project cannot meet the requirement of switching-off the short-circuit current of 63 kA, to meet the requirement of constructing UHV power grids in future, it is necessary to develop the GIS with breaking capability of 63 kA. On the basis of researching and analyzing existing UHV power transmission technologies home and abroad, the overall process of developing 1 100 kV GIS with breaking capability of 63 kA is systemically expounded in aspects of power grid demand, simulation analysis, structural design and type test. The core components of the 1 100 kV GIS with breaking capability of 63 kA are calulated and analyzed theoretically, and the structures of circuit breakers with two-contact and four-contact respectively are designed and simulative verifications of them are performed. After scheme comparison, a scheme to meet the requirement of type test for 1 100 kV GIS with breaking capability of 63 kA is proposed. Finally, according to national standard the type test of circuit breaker with four-contact and that with two-contact are completed. Type test results show that the development and manufacturing of GIS with breaking capability of 63 kA for 1 100 kV power grid can be utterly implemented.