Industry information

"Vacuum circuit breaker" is named because its arc-extinguishing medium and the insulating medium in the contact gap after arc-extinguishing are both high vacuum; it has the advantages of small size, light weight, suitable for frequent operations, and no maintenance for arc-extinguishing. It is widely used in distribution networks. Vacuum circuit breakers are indoor distribution devices in 3 - 10kV, 50Hz three-phase AC systems. They can be used for the protection and control of electrical equipment in industrial and mining enterprises, power plants, and substations. They are especially suitable for use where oil-free, less maintenance and frequent operations are required. Circuit breakers can be configured in mid-mounted cabinets, double-layer cabinets and fixed cabinets to control and protect high-voltage electrical equipment.

In 1893, Rittenhouse of the United States proposed a vacuum interrupter with a simple structure and obtained a design patent. In 1920, the Swedish company Foga made the first vacuum switch. The research results published in 1926 and others also showed the possibility of breaking current in vacuum, but due to the small breaking capacity and the limitations of the development level of vacuum technology and vacuum materials, it has not yet been put into practical use. With the development of vacuum technology, the first batch of vacuum switches suitable for special requirements such as cutting off capacitor banks were manufactured in the United States in the 1950s, and the breaking current still stopped at the level of 4,000 amps. Due to advances in vacuum material smelting technology and breakthroughs made in the research on vacuum switch contact structures, in 1961, the production of vacuum circuit breakers with 15 kV and a breaking current of 12.5 kiloamps began. In 1966, vacuum circuit breakers of 15 kilovolt, 26 kilovolt and 31.5 kilovolt were trial-produced, 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 kiloamps. China began to develop vacuum switches in 1958. In 1960, Xi'an Jiaotong University and Xi'an Switch Rectifier Factory jointly developed the first batch of vacuum switches with 6.7 kV and a breaking capacity of 600 A; subsequently, three-phase vacuum switches with 10 kV and a breaking capacity of 1.5 kiloA were made. In 1969, Huaguang Electronic Tube Factory and Xi'an High-Voltage Electrical Apparatus Research Institute produced a 10 kV, 2 kilovolt single-phase fast vacuum switch. Since the 1970s, China has been able to independently develop and produce vacuum switches of various specifications.