Since the vacuum switch was applied to the power system in the early 1960s, it has a history of more than 40 years. Over the past 40 years, the vacuum switch tube has developed rapidly, especially in the medium voltage field, the share of vacuum switch products has exceeded 85%. From the perspective of development, in addition to improving and further innovating the existing vacuum switch, it can also develop to two aspects of high voltage level and low voltage level, and it is estimated that there will be great potential.

my country has also done a lot of work in this regard, and has launched a 380 V, 1 000 A, 50 kA vacuum switch for low-voltage contactors with general functions. It is reported that Shanghai Institute of Electrical Apparatus has been organizing efforts to develop 400 V, 4 000 A vacuum circuit breakers for low-voltage contactors with intelligent functions, which have the advantages of large breaking current and long service life.

In addition, for the small and medium-sized low-voltage contactors with a large output, a series of fundamental transformations are carried out in the structure to make a miniaturized vacuum contactor with a permanent magnet operating mechanism, which not only has low cost, long service life, but also has a better structure. Compact and smaller. Fig. 9 is the shape of a vacuum interrupter for a miniaturized vacuum contactor. The arc extinguishing chamber exposes all the conventional bellows, and adopts automatic one-time sealing and vacuuming welding in the manufacturing process, which can adapt to mass production, and its price can already compete with conventional air contactors

At present, the development of vacuum switch tubes for contactors in China has reached a relatively stable level, so there is still a certain development prospect in the future market.