直流真空电弧强迫开断电弧形态

发布时间：2018-02-14 10:36

本文关键词： 直流真空电弧强迫开断电弧直径电弧扩散　出处：《电工技术学报》2016年24期 　论文类型：期刊论文

【摘要】：随着航空270V直流系统的应用,直流开关的需求逐渐增加。现阶段直流开关大多为空气开关,其开断容量较小,使用真空开关将对于提高开断容量具有一定优势。针对航空270V直流用短间隙真空灭弧室进行高频开断实验,研究了直流强迫开断的电弧电压、电流特性,分析了回路参数对直流强迫开断中平均电流变化率di/dt和弧后过电压dv/dt的影响。通过相同开断实验电流、相同电流变化率、不同触头结构情况下开断实验,分析了电弧直径动态特性。强迫熄弧过程中,平板触头电弧直径逐渐减小,纵磁触头电弧直径变化较小并在熄弧前迅速变化。针对不同电流实验,随电流升高电弧直径略有增加。起弧阶段,平板触头电弧直径随燃弧时间呈对数函数增加,而纵磁触头电弧直径基本保持不变。拟合得到平板电弧起弧时直径变化函数,随燃弧时间延长,平板触头电弧直径逐渐增大至大于纵磁触头电弧直径。
[Abstract]:With the application of 270V DC system in aviation, the demand of DC switch is increasing gradually. The use of vacuum switch will have some advantages in improving the breaking capacity. The characteristics of arc voltage and current of DC forced breaking are studied by high-frequency breaking experiment on the short-gap vacuum interrupter used in aviation 270V DC. The influence of circuit parameters on the average current change rate (di/dt) and back-arc overvoltage (dv/dt) in DC forced switching is analyzed. The dynamic characteristics of arc diameter are analyzed. In the process of forced arc quenching, the arc diameter of flat contact decreases gradually, the diameter of longitudinal magnetic contact arc changes slightly and changes rapidly before extinguishing arc. The arc diameter of plate contact increases with the arc burning time, but the diameter of longitudinal magnetic contact arc increases with the arc firing time, and the variation function of arc diameter when plate arc starts is obtained by fitting the arc diameter with current increasing slightly, and the arc diameter increases by logarithmic function with arc burning time. With the increase of arc burning time, the arc diameter of flat contact gradually increases to be larger than that of longitudinal magnetic contact.
【作者单位】：北京航空航天大学自动化科学与电气工程学院;
【基金】：国家自然科学基金资助项目(50877002)
【分类号】：V242

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