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 China, the medium voltage vacuum circuit breaker in 2009 accounted for 99.39% of the medium voltage switch. High voltage vacuum circuit breaker in 72.5~126 kV developed a new level, 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 transmission system has been using 72-252kV vacuum circuit breaker 3350.

At present, high voltage vacuum circuit breaker has reached 145 kV single fracture, double fracture of 168 kV, 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, the use of low pressure SF6 gas (such as the pressure of 0.12 MPa) insulation, as well as the use of dry air as an external insulation.

It is worth mentioning that our two high voltage switch mainstream manufacturers of newly developed porcelain vacuum circuit breaker, such as the national Ministry of science and technology project in 2010 from the company successfully completed 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 development of the vacuum interrupter is the first complete intellectual property rights of the product, its technical level 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 type 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.

In the high voltage level, the development of vacuum circuit breaker is the need for the development of the situation, can greatly reduce the amount of greenhouse gases used in SF6, is conducive to environmental protection, reducing the greenhouse effect of the atmosphere. At the same time, the high voltage vacuum circuit breaker has good low temperature resistance, which can avoid the problem of SF6 gas liquefaction in the cold region.

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.. The solution of these technical problems has promoted the progress of vacuum circuit breaker technology. However, the development of high voltage vacuum circuit breaker is in the ascendant.