Research on arc evolution law of arc extin‐ction device under high‐speed large current

Abstract

The lifespan of the guide rail is a bottleneck restricting the operational life of electromagnetic railguns. A well‐designed arc extinguishing device can reduce the arcing erosion caused by residual currents within the guide rail. The CuW alloy is widely used in the high‐pressure arc extinction field due to its excellent electrical and thermal conductivity, high strength, and hardness. Based on the theory of equilibrium state arc plasma, a finite element model of the air arc‐CuW electrode coupling in the arc extinction device was established to study millisecond‐level arc initiation, evolution, extinguishing characteristics, and distribution patterns under extreme and harsh operational conditions with a current input of 110 kA. The highest temperature in the arc column region was found to exceed 50,000 K. The study elucidated the influence of arc extinction device parameters on arc evolution, breakdown time, and breakdown voltage. Consequently, it established that the R70 spherical electrode exhibits optimal arc extinguishing characteristics. The aim of this research is to provide theoretical support for optimizing the arc suppression device. Additionally, experiments on high‐speed and high‐current arc extinction device discharges were conducted to validate the finite element analysis results regarding arc diffusion patterns and electrode erosion.