Abstract:

A systematic investigation is conducted on the arc characteristics of aviation 230 V variable-frequency AC contactors in gas and vacuum media,with the influence of different gas media,gas pressure,contact materials,and current frequency on arc characteristics and arc-extinguishing performance analyzed.By building a dedicated experimental platform,the arc-extinguishing performance of hydrogen,argon,helium,nitrogen,and other gases was compared.The influence of pressure variations on the arc characteristics of hydrogen was systematically analyzed,the ablation resistance of various contact materials was evaluated,and the impact of contact diameter,materials,and current frequency on arc interruption capability in a vacuum environment was thoroughly investigated.The results indicate that hydrogen exhibits optimal arc-extinguishing performance,with a steady-state arcing voltage of 60 V,significantly higher than other gas media.The CuCr series materials demonstrate outstanding performance in ablation resistance and interruption capability,making them ideal contact materials.The current frequency in the range of 360~800 Hz has a significant impact on arc energy,chopping current,and interruption capability,with the vicinity of 600 Hz being the weakest frequency band for interruption capability.A relatively complete database of arc characteristics is established,providing important theoretical and experimental basis for the optimized design of aviation variable-frequency AC contactors.

Key words: aviation contactor, variable-frequency AC, arc characteristics, gas medium, vacuum arc-extinguishing, contact material, frequency characteristics