多段微孔结构中电弧的磁流体模型及气吹灭弧性能仿真  

MHD Model of Arc in Multi-segment Microhole Structure and Simulation of Air-blowing Arc-quenching Performance

作　　者：司马文霞[1] 贾文彬[1] 袁涛[1] 许航[1] 杨鸣[1] 

机构地区：[1]重庆大学输配电装备及系统安全与新技术国家重点实验室,重庆400030

出　　处：《高电压技术》2016年第11期3376-3382,共7页High Voltage Engineering

基　　金：国家重点基础研究发展计划(973计划)(2015CB251003)~~

摘　　要：由于并联间隙自熄弧能力弱,当线路遭受雷击时并联间隙冲击闪络后易出现稳定的工频续流电弧,引起线路频繁跳闸从而限制其应用,因此如何提高并联间隙的自熄弧能力具有重要的研究价值。多段微孔结构具有优异的灭弧性能,将其运用于并联间隙可显著提高并联间隙的自熄弧性能,故基于磁流体动力学(MHD)理论,利用COMSOL Multiphysics软件建立了2维多段微孔结构中电弧的MHD模型,并仿真分析了该结构中电弧的运动特性及该结构的灭弧性能。仿真结果表明:电弧的MHD模型能很好的反映多段微孔气吹灭弧结构中电弧的运动过程;当短路电弧电流幅值分别为1 k A、2 k A、5 k A时,微孔喷口处最大气流速度可分别达到520 m/s、813 m/s、1 027 m/s,即电流越大加热空气效果越显著,空气受热膨胀后气流的运动速度越大;该灭弧结构中气流运动速度达到气吹熄弧要求的时间在1 ms以内。Due to limited ability of arc extinction of parallel gaps have very, steady power frequency following current can arise easily when parallel gaps are broken down by lightning, which will increase lightning trip-out rate and limit parallel gaps＇ application. Clearly, it is of great significance to improve the arc-quenching ability of parallel gaps. Multi-segment microhole structure has excellent arc-quenching performance. It is widely believed that applying the structure to parallel gaps can significantly improve the arc-quenching ability of parallel gaps. Hence, a two-dimensional magneto-hydrodynamics （MHD） model of arc in multi-segment microhole structure is established in the COMSOL Multiphysics software. Also, the arc movement characteristics of arc extinguishing structure and arcing mechanism are simulated. Simulation results indicate that the arc MHD model can well describe the arc movement in arc extinguishing structure. When the amplitudes of short circuit arc current are 1 kA, 2 kA, and 5 kA, the amplitude of airflow velocity through the micromoles can reach 520 m/s, 813 m/s and 1 027 m/s, respectively. That is, the higher the current is, the more significant the air＇s heated effect will be. Therefore, the speed of airflow after air＇s heat expansion becomes faster. The speed of airflow in multi-segment microhole structure, which is needed to extinguish the arc, can be reached within 1 ms.

关 键 词：电弧放电 MHD模型 电弧分段 气吹灭弧 有限元法 并联间隙 

分 类 号：TM863[电气工程—高电压与绝缘技术]