Dynamic Characteristics Analysis of 550 kV Fast Circuit Breaker Repulsion Valve

The conventional 550 kV circuit breaker operating mechanism has a long start-up time, which cannot meet the requirements for rapid disconnection. This paper proposes a design scheme for a fast circuit breaker operating mechanism using a repulsion valve, establishes a simulation model for the valve's motion characteristics, calculates the effects of structural parameters of the repulsion mechanism and excitation coil parameters on the dynamic characteristics of the fast valve, and obtains the design parameter configuration for the repulsion module. The research results show that the structural parameters of the repulsion mechanism and the excitation coil have a significant impact on the motion characteristics of the repulsion valve. By adopting a design scheme with a repulsion disc radius and excitation coil radius of 80 mm, a repulsion disc thickness of 10 mm, 30 turns of the excitation coil, an excitation coil thickness of 5 mm, and an initial air gap of 1 mm, the action times for single and dual repulsion mechanisms are 1.74 ms and 1.52 ms, respectively. Based on the simulation results, a prototype was developed, and a mechanical characteristic test platform was built. The measured start-up time of the new fast hydraulic operating mechanism is 2.59 ms. The research findings provide theoretical support for the development of the fast repulsion valve.