High-voltage circuit breakers can be classified in various ways, including by arc-extinguishing medium, installation location, and structural form. Among these, classification based on the arc-extinguishing medium is key to distinguishing different circuit breaker technologies and application scenarios.
Classification by arc-extinguishing medium mainly includes sulfur hexafluoride (SF6) circuit breakers, vacuum circuit breakers, oil circuit breakers, compressed air circuit breakers, and magnetic blowout circuit breakers. SF6 circuit breakers use SF6 gas as both the arc-extinguishing and insulating medium, and their arc-extinguishing capacity is equivalent to 100 times that of air under the same conditions. They are the mainstream equipment in modern ultra-high voltage and extra-high voltage power grids. my country has successfully developed the world's first 800 kV/80 kA large-capacity circuit breaker. Vacuum circuit breakers utilize vacuum as the arc-extinguishing medium and mainly dominate the medium-voltage field. They are widely used in power systems of 35 kV and below and are trending towards replacing oil circuit breakers. Their contact materials often use CuCr alloy. Oil circuit breakers include multi-oil circuit breakers and low-oil circuit breakers, using insulating oil as the arc-extinguishing medium. These types of circuit breakers are being phased out. Compressed air circuit breakers use compressed air as the arc-extinguishing medium and can serve as a backup solution in ultra-high voltage fields. Magnetic blowout circuit breakers use a magnetic field to drive the arc movement to enhance the arc-extinguishing effect and are suitable for special scenarios.
Based on installation location, circuit breakers can be divided into indoor and outdoor types. Outdoor circuit breakers are installed outdoors and must withstand harsh environmental conditions such as wind, rain, and pollution.
