The extinguishing of the vacuum arc is based on the use of the high dielectric strength of the high vacuum medium and the high diffusion speed of the arc products (charged particles and metal vapor) in this rarefied gas, so that the contact gap after the arc current crosses zero. It is realized by the principle that the strength of the medium can be quickly recovered. The metal vapor and charged particles in the arcing process are condensed by the shielding cover in the strong diffusion, and the arc running surface with the spiral groove makes the arc move rapidly along the tangential direction. As a result, the temperature of the main contact surface is lowered, so its insulation recovery is fast, which forces the arc to extinguish when the current crosses zero.

Vacuum circuit breaker: internal structure diagram of high voltage vacuum circuit breaker

Insulation cylinder, soft connection, insulation rod, four-bar linkage, upper bracket, lower bracket, four-bar linkage, opening electromagnet, lower outlet socket, circuit breaker housing, closing cam, vacuum interrupter, disc spring , Opening spring.

The main structure of the high-voltage circuit breaker is roughly divided into: the diversion part, the arc extinguishing part, the insulating part, and the operating mechanism part. The main types of high-voltage switches are divided into: oil circuit breakers, air circuit breakers, vacuum circuit breakers, sulfur hexafluoride circuit breakers, solid gas generating circuit breakers, and magnetic blowing circuit breakers. According to the nature of operation, it can be divided into: electric mechanism, pneumatic mechanism, hydraulic mechanism, spring energy storage mechanism, manual mechanism.

Oil circuit breaker. Using transformer oil as arc extinguishing medium, there are two types: more oil and less oil.

Sulfur hexafluoride circuit breaker. The inert gas sulfur hexafluoride is used to extinguish the arc, and its high insulating properties are used to enhance the insulation between the contacts.

vacuum circuit breaker. The contact is sealed in a high vacuum arc extinguishing chamber, and the arc is extinguished by using the high insulation performance of the vacuum.

air circuit breaker. Use high-speed compressed air to extinguish the arc.

Solid gas production circuit breaker. The arc is extinguished by using the gas decomposed by the solid gas-producing material under the action of the high temperature of the arc.

Magnetic blower circuit breaker. When the circuit is broken, the electromagnetic force generated by the large current flowing through itself is used to quickly elongate the arc and cool it out in the magnetic arc extinguishing chamber.