Research and development of self-energy SF6 circuit breaker on the breaking capacity

By improving of the dielectric performance between the breakers, medium condition and arc extinguishing ability, the breaking capacity of circuit breaker is increased. The main architecture of the 252kV circuit breaker is determined in which double chamber of interrupter construction + dual-direction moving of contacts mode are introduced. The key structure design parameter have been optimized combined with the design experiences of the finalized product: The volume of thermal expand chamber and puffer chamber as well as the cooperation between them are determined which ensures the breaking of the high current. Electric field analysis software is used to calculate, analyze and optimize the electric field strength of the circuit breaker contacts in some sensitive positions. Improving airflow channel for the decrease of the gas density is to be restrained and the hot gas exhaust efficiency is to be increased. As a result, the medium condition is improved. All the test verification has achieved for the researched and developed circuit breaker, and the product have been on stream. In the meantime, it provides the new technical foundation for the various following switchgears.