"High-voltage vacuum circuit breaker" is named because its arc extinguishing medium and the insulating medium of the contact gap after arc extinguishing are both high vacuum, it has the advantages of small size, light weight, suitable for frequent operation, and arc extinguishing without maintenance, and is widely used in distribution networks.
Brief history of development In 1893, Rittenhouse proposed a simple vacuum arc extinguishing chamber. In 1920, the Swedish Foga Company made a vacuum switch for the first time. The research results published in 1926 also showed the possibility of breaking current in a vacuum, but due to the small breaking capacity and the limitations of the development level of vacuum technology and vacuum materials, it could not be put into practical use. With the development of vacuum technology, the United States only made the first batch of vacuum switches suitable for cutting off capacitor banks and other special requirements in the 1950s, and the breaking current was still at the level of 4 kiloamperes. Due to the progress in vacuum material smelting technology and the breakthrough in the research of vacuum switch contact structure, in 1961, the production of 15 kV vacuum circuit breakers with a breaking current of 12.5 kA began. In 1966, 15 kV, 26 kA and 31.5 kA vacuum circuit breakers were trial-produced, thus allowing vacuum circuit breakers to enter high-voltage, large-capacity power systems. In the mid-1980s, the breaking capacity of vacuum circuit breakers reached 100 kA. China began to develop vacuum switches in 1958, and in 1960 developed the first batch of 6.7 kV vacuum switches with a breaking capacity of 600 A, subsequently, 10 kV three-phase vacuum switches with a breaking capacity of 1.5 kA were produced. In 1969, a 10 kV, 2 kA single-phase fast vacuum switch was produced. After the 1970s, China has been able to independently develop and produce vacuum switches of various specifications. Before the 1980s, vacuum circuit breakers were in the initial stage of development, and the technology was constantly being explored. Technical standards could not be formulated until after 1985.