Dynamic Characteristics of 550 kV Fast Circuit Breaker Operating Mechanism

Conventional operating mechanisms suffer from inherent limitations including prolonged response time and inadequate driving speed, which fail to satisfy the stringent opening time requirements of 550 kV fast circuit breakers. To address this, we propose a novel operating mechanism with fast response and high-speed motion, establishing a coupling relationship between the repulsion mechanism and the hydraulic mechanism. A simulation model of the dynamic characteristics of the novel operating mechanism was constructed, and a multi-objective optimization algorithm was used to refine the repulsion mechanism's design. The fast response characteristics, high-speed drive characteristics, and cushioning characteristics of the operating mechanism are analyzed. The research shows that with a repulsion mechanism design featuring an energy storage capacitor capacity of 7787 μF, a charging voltage of 1033 V, 45 coil turns, a coil thickness of 9 mm, a coil width of 2 mm, a repulsion plate thickness of 8 mm, and a repulsion plate radius of 103 mm, fast response is achieved in coordination with the hydraulic valve, reducing start-up time to 2.35 ms. With a hydraulic mechanism piston rod action area of 3160 mm², the opening speed increases to 13.63 m/s, and the mechanical separation time of the contacts is reduced to 4.45 ms. An ideal cushioning structure was proposed. The research results successfully guided the development of a prototype fast operating mechanism.