基于IEC安全火花试验装置的电感分断放电电极热-电耦合的数值研究  

A Numerical Study on the Thermal-Electrical Coupling of the Inductor Disconnected Electrode Based on the IEC Safety Spark Test Apparatus

作　　者：成福群[1] 吴疆 赵永秀[3] 王瑶 CHENG Fuqun;WU Jiang;ZHAO Yongxiu;WANG Yao(Chongqing Electric Power College,Chongqing 400053,P.R.China;State Grid Chongqing Integrated Energy Service Co.,Ltd.,Chongqing 400024,P.R.China;School of Electrical and Control Engineering of Xi'an University of Science and Technology,Xi'an Shanxi 710054,P.R.China)

机构地区：[1]重庆电力高等专科学校,重庆400053 [2]国网重庆综合能源服务有限公司,重庆400024 [3]西安科技大学电气与控制工程学院,陕西西安710054

出　　处：《重庆电力高等专科学校学报》2023年第6期1-7,共7页Journal of Chongqing Electric Power College

基　　金：重庆市教育委员会2020年高等教育教学改革研究项目(203595);国家自然科学基金资助项目(51777167)。

摘　　要：研究基于IEC安全火花试验装置的电感分断弧前金属液态桥的形成是研究低压、小电流感性电路分断电子产生机制及电弧形成机理的关键。考虑镉盘电极微观表面形貌,基于流体动力学模型,建立了真空环境下钨丝-镉盘电极热-电耦合的几何与数学模型。数值模拟了极间金属液桥的形成过程,得出了液桥的温度分布、固-液相变过程和电压特性;探究了电路串联电感、初始电流及电极初始接触压力对金属液桥形成的影响。数值模拟计算结果表明,模型最高温度出现在接触区域中心,金属液桥形变受热膨胀力与马兰格尼效应共同作用;当接触区域温度均达到镉材料的沸点时,金属液桥完全断裂,此时电极两端电压与实验测量得到的最小建弧电压相符;电路电感大小对金属液桥形成基本无影响,而增大初始电流或减小电极初始接触压力会缩短电极熔化、金属液桥蒸发及完全断裂所需时间。这为进一步探究低压、小电流感性电路分断放电电弧形成及引燃机理提供了理论指导意义。The research on the formation of the metal liquid bridge before the inductor disconnected discharge(IDD)based on the IEC safety spark test apparatus is the key to studying the electron generation mechanism and the arc formation mechanism of the low voltage and small current IDD circuit.Considering the microscopic surface morphology of the cadmium electrode,the geometric and mathematical models of the tungsten-cadmium electrode thermal-electrical coupling in a vacuum are established based on a hydrodynamics model.The formation process of the inter-electrode metal liquid bridge is simulated in a numerical way,and the temperature distribution,solid-liquid phase transition and voltage characteristics of the metal liquid bridge are obtained.The influence of the circuit series inductance,initial current and electrode initial contact pressure on the formation of the metal liquid bridge is explored.The results of the numerical simulation show that the highest temperature of the model is at the center of the contact position,and the deformation of the metal liquid bridge is affected by the thermal expansion stress and the Marangoni effect.When the temperature of the contact position reaches the boiling point of the cadmium material,the metal liquid bridge is completely broken,and hte voltage across the electrode is consistent with the minimum arc-building voltage measured in the experiment.The formation of the metal liquid bridge ishardly affected by the circuit inductance,while increasing the initial current or decreasing the initial contact pressure of the electrode will shorten the time required for themelting of the electrode,the evaporation of the metal liquid bridge and the complete fracture,which provides theoretical guidance for further researches on the mechanism of the low voltage and small current IDD arc formation and ignition.

关 键 词：IEC安全火花试验装置 电感分断放电 热-电耦合 金属液桥 低压小电流 

分 类 号：TM501.2[电气工程—电器]