The development of high voltage vacuum circuit breaker technology is promising.
In the field of medium voltage vacuum circuit breakers (12-40.5 kV) has been dominant, and in the field of high voltage (72.5-252 kV) has also been budding, optimistic about the prospects for its development. In our country, the medium voltage vacuum circuit breaker has occupied 99.39% of the medium voltage switch in 2009. High voltage vacuum circuit breaker in 72.5~126 kV level continuously developed, and has been put into operation. In foreign countries, many countries and companies in the development of high voltage vacuum circuit breaker, and some products have been put into operation for many years, such as Japan, South Korea, the United States, Germany, Russia, etc.. According to statistics, the Japanese power transmission system has been using 72-252kV vacuum circuit breaker 3350 sets. At present, the high voltage vacuum circuit breaker has reached 145 kV single fracture, 168 kV double fracture, is now developing a higher voltage grade products. Products are tank and porcelain in the structure, our country has made porcelain column 126 kV vacuum circuit breaker, and Japan 168 kV vacuum circuit breaker using the tank structure. In the vacuum arc extinguishing outdoor insulation, useful low pressure SF6 gas, such as (internal pressure 0.12 MPa) insulation, but also useful for the external insulation of dry air and so on.
It is worth mentioning that our two high voltage switch mainstream manufacturers of newly developed porcelain vacuum circuit breaker, such as the 2010 electricity company successfully completed the national Ministry of science and technology 126 kV vacuum circuit breaker, and through the national Ministry of science and technology acceptance. The product vacuum arcing chamber adopts coil structure and longitudinal magnetic field, the use of copper chromium contact materials with high breaking capacity and good anti welding. The developed vacuum arc extinguishing chamber is the first complete intellectual property product in China, and its technical level is in the international advanced level. Another is the high level group and high level group in the development of high voltage and large capacity SF6 circuit breaker at the same time, but also to seize the opportune moment to develop high voltage vacuum circuit breaker. The group in November 2011 at the same time the LW55-72.5 type tank SF6 circuit breaker ZW55-63 high voltage vacuum circuit breaker, ZW55-2 * 31.5 and ZW55-31.5 type vacuum circuit breaker of 4 kinds of new products of national identification, the overall reached the international advanced level.
At the Hannover exposition in 2011, SIEMENS unveiled the use of nitrogen (N2) 72.5 kV vacuum circuit breaker insulation to replace the traditional SF6 circuit breaker, the SIEMENS company began to focus on the development of high voltage vacuum circuit breaker. At the high voltage level, the development of vacuum circuit breaker is the need of the development of the situation, can greatly reduce the use of SF6 greenhouse gas, is conducive to environmental protection, reduce the greenhouse effect in the atmosphere. At the same time, the high voltage vacuum circuit breaker has good low temperature resistance characteristics, which can avoid the problem of SF6 gas liquefaction in the cold area. It is the best choice for the high voltage grade circuit breaker in the cold area. To solve a series of technical problems in the development of high voltage vacuum circuit breaker: high voltage vacuum insulation, high current vacuum interrupter, rated current and temperature, mechanical properties, vacuum interrupter insulation and capacitive current breaking, inductive current breaking etc.. These technical problems have been solved, which have promoted the progress of the vacuum circuit breaker technology. However, the development of high voltage vacuum circuit breaker is in the ascendant, and it is necessary to carry out research work.