Time Scatter Analysis of 800kV Fast Circuit Breaker

The closing process of UHV converter transformer / transformer will produce magnetizing inrush current. Phase selection technology is an important method to suppress inrush current. This requires the circuit breaker to have faster speed and lower time scatter, so as to predict and compensate closing time. 800 kV fast circuit breaker uses the electromagnetic repulsion mechanism instead of the original solenoid valve. The above method can improve the speed of the valve core during the circuit breaker tripping process and reduce the tripping time. In this paper, the time scatter of solenoid valve and electromagnetic repulsion mechanism under different driving voltage and ambient temperature is compared and analyzed. It shows that the electromagnetic repulsion release method has the advantages of faster speed and lower time scatter, which is suitable for the phase selection scene. The mathematical model of hydraulic mechanism and transmission system is established based on the theory of hydraulic fluid mechanics and the second Lagrange equation. The article further analyzes the characteristics of the hydraulic mechanism output and reaction force under different oil pressure, arc extinguishing chamber pressure, ambient temperature conditions, and obtains its time scatter. This study provides a reference for the phase selection compensation scheme of 800 kV fast circuit breaker.