The technology of SF_6 circuit breakers has become well established at all high-voltage levels during the last two decades. Most of the SF_6 breakers in service today are of the puffer-type. They generate the pressure necessary for arc extinction by mechanical compression during the breaking performance. The puffer breakers can be considered as the second generation of SF_6 switchgear. In SF_6 breakers of the first generation from the early days of SF_6 technology, the sulfur-hexafluoride was stored permanently at the high level of the extinguishing pressure. Because of problems with SF_6 liquefaction, these first generation breakers were not of any greater importance.
展开▼
