There are many types of high-voltage circuit breakers, and they can generally be classified according to the following methods: according to the installation location of the circuit breaker, they can be divided into indoor and outdoor types; according to the arc extinguishing principle or arc extinguishing medium of the circuit breaker, they can be divided into oil circuit breakers, Vacuum circuit breakers, sulfur hexafluoride (SF6) circuit breakers, etc.
Circuit breakers that use insulating oil as the arc extinguishing medium are called oil circuit breakers. It can be divided into more oil circuit breaker and less oil circuit breaker.
In addition to being used as an arc extinguishing medium, the insulating oil in a multi-oil circuit breaker is also used as the main insulation between the contacts and the main insulation between the live part and the grounded shell after the contacts are disconnected. The multi-oil circuit breaker has oil consumption Many, large amount of metal consumables, prone to fire or explosion, large size, low processing technology requirements, durable, low price, etc. At present, in the electric power system, except for the 35kV and other individual models of outdoor multi-oil circuit breakers are still in use, the production and use of other multi-oil circuit breakers have been stopped.
The insulating oil in the low-oil circuit breaker is mainly used as an arc extinguishing medium, and the insulation between the live part and the ground mainly uses insulators or other organic insulating materials. This type of circuit breaker is called a low oil circuit breaker because it uses less oil. Oil-less circuit breakers have the advantages of less consumables and low prices, but they require regular maintenance, which may cause fire and explosion. Although oil-less circuit breakers are currently in use, they have been gradually replaced by vacuum circuit breakers and SF6 circuit breakers.
A vacuum circuit breaker is a circuit breaker that uses "vacuum" as an insulating medium and an arc extinguishing medium. The so-called "vacuum" here can be understood as a rare gas space whose gas pressure is far below one atmosphere, and gas molecules in the space are extremely rare. A vacuum circuit breaker is a circuit breaker made by installing its moving and static contacts in a "vacuum" sealed container (also called a vacuum interrupter).
Sulfur hexafluoride (SF6) circuit breakers are circuit breakers that use SF6 gas with high-quality insulation and arc extinguishing performance as the arc extinguishing medium. SF6 circuit breaker has the advantages of strong arc extinguishing performance, no spontaneous combustion, and small size.