Why vacuum circuit breakers in HV?
Because of great harmfulness of greenhouse effect, SF6 gas has to be limited. It is necessary to develop high voltage vacuum circuit breaker to replace SF6 circuit breaker. Insulating structure and arc-characteristics of vacuum interrupter are the key to development of high voltage vacuum circuit breakers.
Let’s start this article with brief history, then device implications and differences between Vacuum / SF6 and finally 245kV prototype and some example specifications: