Simulation Research on Driving Technology and Influence Factors of Double-layer Coil Type Rapid Repulsive Mechanism of 40.5kV Vacuum Circuit Breaker

Abstract

Circuit breakers are important control and protection devices in power systems and are essential for ensuring safe and reliable operation of power systems. In recent years, the application of fast electromagnetic repulsive mechanism based on the principle of eddy current in vacuum circuit breaker has gradually become a hot research topic. However, due to the large mass of the moving mechanism and the large opening distance in the high voltage vacuum circuit breaker, it is difficult for the ordinary mechanism to break quickly. Therefore, a double-layer coil type fast electromagnetic repulsive mechanism is proposed, which can generate a larger electromagnetic repulsive force to achieve fast driving of the mechanism. Taking the 40.5kV/50kA vacuum circuit breaker as an example, the 2D finite element model was built by MAXWELL software, and its motion characteristics were simulated. In addition, the effect of the metal plate thickness, coil inner radius, number of coil turns and initial gap on the motion characteristics of the fast electromagnetic repulsive mechanism is investigated. The results show that the rise time of the electromagnetic repilsive force is very short. In contrast, the electromagnetic repilsive force has a long time to fall, and the peak value of the electromagnetic repilsive force is large. Thickening the metal plate, increasing the inner radius of the coil plate, increasing the number of coil turns and reducing the initial gap can increase the speed of the rapid electromagnetic repulsive mechanism. The simulation analysis provides a basis for further design of the electromagnetic repilsive mechanism.