Advances In High Voltage Vacuum Circuit Breaker Technology

Outdoor high-voltage vacuum circuit breakers (pole-mounted vacuum circuit breakers) have an absolute advantage in the medium-voltage field (12-40.5kV), and have also emerged in the high-voltage field (72.5-252kV), and their development prospects are promising. In my country, medium-voltage vacuum circuit breakers accounted for 99.39% of medium-voltage switches in 2009. High Voltage Vacuum Circuit Breaker has also continuously developed new products at the 72.5~126kV level, and has been put into operation. Abroad, many countries and companies are developing high-voltage vacuum circuit breakers, 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, 3,350 72-252kV vacuum circuit breakers have been used in Japan's power transmission system. At present, high-voltage vacuum circuit breakers have reached 145kV single-break and 168kV double-break, and products with higher voltage levels are being developed. The product has two structures: tank type and porcelain column type. my country has produced porcelain column type 126kV high-voltage vacuum circuit breakers, while Japan's 168kV vacuum circuit breakers use tank structure. For the external insulation of the vacuum interrupter, low-pressure SF6 gas (internal filling pressure 0.12MPa) is used for insulation, and dry compressed air is also used as external insulation.