Application experience of SF6-Free 72.5kV hybrid-gas-insulated-switchgears in China

摘要

Vacuum switchgear technology is widely used in the worldwide in all kinds of medium-voltage distribution system for its outstanding technical performance and low life-cycle costing. Now, some manufactures have started to expand this technology to high voltage transmission level. A new developed SF₆-Free Hybrid-Gas-Insulated-Switchgear in China is introduced in this paper, which uses a single vacuum interrupter for arc-quenching and dry-air for dielectric insulation, the earthing switches and disconnectors are also operated in dry air. A common spring drive mechanism is used to switch the vacuum interrupter unit inside of the three dead tank poles. The developed SF₆-Free H-GIS was delivered to two pilot customers in China to gather joint operation experience under the realistic network conditions. The paper deals with the basic information about the switchgear design and their early application experience.