Medium voltage gas insulated switchgear highest reliability and availability under severe climatic conditions in urban networks

摘要

with the raising energy demand in high density areas, such as in down-town city centres, the space for extensions, respectively up-grading of existing switchgear is limited. Consequently, a new concept in form of medium voltage gas-insulated (fully encapsulated) switchgear with space-saving dimensions was the most suitable solution. Contrary to the high voltage concept, which incorporates SF{sub}6 circuit breakers, the medium voltage concept was based on the at this time well proven vacuum switching technology, offering a nearly maintenance-free solution. ALSTOM developed and promoted the first gas-insulated switchgear during the end of the seventies/begin of the eighties.