Valve Hall Earthing Switch, ZJN-1100

The ZJN-1100 ultra-high voltage valve hall earthing switch was developed as part of the world’s only ±1100kV DC transmission project, featuring an innovative structural breakthrough. It replaces the conventional vertical roller-type design with a horizontal folding insertion structure, achieving a record-breaking contact gap of over 15 meters, making it the longest-gap grounding switch in the world.

This pioneering achievement has filled a critical technological gap both domestically and internationally and has been granted a national invention patent. Since September 2019, it has been in operation in the Changji–Guquan ±1100kV UHVDC transmission project, the world’s most advanced ultra-high voltage transmission system, distinguished by the highest voltage level and cutting-edge technology.