Abstract:

C₄F₇ N/CO₂ mixture gas is a new type of environmentally friendly gas,and the study of its arc characteristics is of great significance to the development of a new type of SF₆ to replace the gas circuit breaker.This paper takes SF₆,CO₂ and C₄F₇ N-90%CO₂ mixture as the research object,and establishes the arc model of CO₂,SF₆,C₄F₇ N/CO₂ mixture under the conditions of DC power supply,single nozzle and fixed electrode.The main difference of breaking performance between C₄F₇N/CO₂ mixture gas,pure CO₂ gas and SF₆ gas and the physical parameters closely related to breaking performance are found by analyzing the arc radial temperature distribution and arc energy diffusion velocity.The results show that under the same conditions,the radial temperature distribution of C₄F₇N/CO₂ mixture gas is closer to that of SF₆ gas,its radial heat transfer ability is stronger,and the arc heat dissipation rate is faster,which indicates that C₄F₇N/CO₂ mixture gas has better arc extinguishing characteristics,and can be used in the development of SF₆ gas circuit breaker.

Key words: C₄F₇N/CO₂ gas mixture, SF₆ alternative gas, arc, physical parameters