Use and type of high voltage circuit breaker

The high voltage circuit breaker plays a controlling role in the high voltage circuit and is one of the important electrical components in the high voltage circuit. The circuit breaker is used to turn on or off the circuit during normal operation. The fault condition is quickly disconnected from the circuit by the relay protection device, and the short-circuit current is reliably turned on under special circumstances (such as when automatically reclosing to the faulty line). A high voltage circuit breaker is a special electrical appliance that turns a high voltage circuit on or off under normal or fault conditions.

The types of high-voltage circuit breakers are various and can be classified according to the following methods: According to the installation location of the circuit breakers, they can be divided into indoor and outdoor types. According to the principle of arc-breaking of circuit breakers or arc-extinguishing media, oil circuit breakers can be classified. Vacuum circuit breakers, sulfur hexafluoride circuit breakers, etc.

1, oil circuit breaker

A circuit breaker using insulating oil as an arc extinguishing medium is called an oil circuit breaker. It can be divided into multi-oil circuit breakers and oil-less circuit breakers.

In addition to the use of the arc extinguishing medium, the insulating oil in the multi-oil circuit breaker is also used as the main insulation between the contacts after the contacts are disconnected and the main insulation between the live parts and the grounded casing, and the multi-oil circuit breaker has the oil consumption. Many, metal consumables are large, prone to fire or explosion, large volume, low processing requirements, durable, low price and so on. At present, in addition to the use of individual models of outdoor multi-oil circuit breakers such as 35kv in the power system, the remaining multi-oil circuit breakers have stopped production and use.

The insulating oil in the oil-less circuit breaker is mainly used as an arc extinguishing medium, and the insulation between the live part and the ground is mainly made of porcelain bottle or other organic insulating material. This type of circuit breaker is called a low oil circuit breaker because it uses less oil. The oil-less circuit breaker has the advantages of low consumables and low price, but it needs regular maintenance and has the risk of causing fire and explosion. Although the oil-less circuit breaker is currently in use, it has gradually been replaced by new circuit breakers such as vacuum circuit breakers and sulfur hexafluoride circuit breakers.

2, vacuum circuit breaker

The 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 gas space where the gas pressure is much lower than one atmosphere, and the 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 known as a vacuum interrupter).

3. SF6 circuit breaker

The sulphur hexafluoride circuit breaker is a circuit breaker that uses sulfur hexafluoride gas with high quality insulation performance and arc extinguishing performance as an arc extinguishing medium. The sulphur hexafluoride circuit breaker has the advantages of strong arc extinguishing performance, no spontaneous combustion, and small volume.