The use of a vacuum for switching electrical currents was motivated by the observation that a one-centimeter gap in an X-ray tube could withstand tens of thousands of. Although some vacuum switching devices were patented during the 19th century, they were not commercially available. In 1926, a group led by Royal Sorensen at the investigated vacuum switching and tested several devices; fundamental aspects of arc interrupti.
The vacuum circuit breaker can be used in a much lighter construction, as a contactor for motor switching applications at voltages of up to 12 kV The lifespan of typical vacuum circuit breakers is very long (usually 20,000 switching and a hundred short circuit operations) before replacement is required.
Over the last decades Vacuum Circuit Breakers (VCBs) are the most preferred switching devices in the medium voltage levels up to 52 kV. More than 80% of today's new installation employs vacuum switching technology .
Can a fast vacuum circuit breaker interrupt a fault current?
Fast vacuum circuit breaker can interrupt a fault current in the first half-cycle. Fast vacuum switching technology is promising for accurate controlled switching. Future power systems could benefit from the application of fast vacuum switches. Vacuum switching technology is changing the future of power systems.
The fundamental principle behind a Vacuum Circuit Breaker is the use of a vacuum as the arc quenching medium. When an overcurrent or short circuit occurs, the circuit breaker's contacts are forced to open, creating an arc due to the current flow. In a VCB, this arc is quickly extinguished as it enters a vacuum environment.
What are the advantages of vacuum circuit breakers?
The use of Vacuum Circuit Breakers offers several advantages over other types of circuit breakers: VCBs are known for their high reliability, with fast and efficient arc interruption capabilities. Due to their simple and robust design, VCBs require minimal maintenance, resulting in cost savings and increased uptime.
By the mid-1960s, General Electric (GE) Corporation (USA) developed a 15 kV/1.2–12 kA vacuum circuit breaker (VCB) which was the first VCB product worldwide. At the same period, Xi'an Jiaotong University developed the first three-phase vacuum switch in China in 1965, which was with 10 kV and 1500 A.