The principle and application of high-voltage circuit breakers

“High-pressure vacuum circuit breaker” is named so because both the arc extinguishing medium and the insulation medium between the contacts after arc extinguishing are high vacuum. Vacuum circuit breakers have the advantages of small size, light weight, suitability for frequent operations, and no need for maintenance during arc extinguishing. They are widely used in power distribution networks. Development history: In 1893, Rittenhouse from the United States proposed a simple structure vacuum arc extinguishing chamber and obtained a design patent. In 1920, the Swedish Foga Company produced a vacuum switch. In 1926, the published research results 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, they could not be put into practical use yet.
With the development of vacuum technology, it was not until the 1950s that the United States produced vacuum switches suitable for special requirements such as cutting capacitor banks. The breaking current was still at the level of 4 kiloamperes. Thanks to the progress in vacuum material smelting technology and the breakthroughs made in the research on the structure of vacuum switch contacts, in 1961, vacuum circuit breakers with a voltage of 15 kilovolts and a breaking current of 12.5 kiloamperes began to be produced. In 1966, vacuum circuit breakers with a voltage of 15 kilovolts and breaking currents of 26 kiloamperes and 31.5 kiloamperes were successfully tested. This enabled vacuum circuit breakers to enter high-voltage and large-capacity power systems. In the mid-1980s, the breaking capacity of vacuum circuit breakers reached 100 kiloamperes. China began to develop vacuum switches in 1958. In 1960, Xi’an Jiaotong University and Xi’an Switch Rectifier Factory jointly developed a batch of vacuum switches with a voltage of 6.7 kilovolts and a breaking capacity of 600 amperes; subsequently, a three-phase vacuum switch with a voltage of 10 kilovolts and a breaking capacity of 1.5 kiloamperes was also produced. In 1969, Huaguang Electronic Tube Factory and Xi’an High Voltage Electrical Apparatus Research Institute produced a single-phase rapid vacuum switch with a voltage of 10 kilovolts and a breaking current of 2 kiloamperes. Since the 1970s, China has been able to independently research and produce vacuum switches of various specifications.