Research on Mechanism Design Scheme of 500kv Fast Circuit Breaker

Abstract

Reducing the fault isolation time of 500kV transmission line is of great significance for enhancing the transmission capacity of transmission line and improving the security and stability of power grid. In this paper, the CTY-5/10/20 series hydraulic operating mechanism is improved. The electromagnetic repulsion mechanism is used to drive the hydraulic valve directly in the 500kV fast circuit breaker mechanism, which cancels the response time of the primary valve of the original transmission hydraulic mechanism. Finally, the action time of the mechanism is reduced to 4ms to achieve the fast response of the mechanism, and then the breaking time of the circuit breaker is reduced. Through simulation and test verification, the average opening speed of the improved 500kV fast circuit breaker mechanism can reach 10m / s, and the opening time is about 8mm.The research results of this paper accumulate experience for the future engineering application of 550kV fast AC circuit breaker in China Southern Power Grid, and provide reference for the future planning and safe and stable operation of China Southern Power Grid.