The Influence of Medium on Low-Voltage Circuit Breaker Arcs

This paper mainly focuses on the influence of three kinds of media： air, air-10%PA （Nylon） and air-10% POM （polyoxymethylene） on low-voltage circuit breaker arcs. A threedimensional （3-D） model of arc motioa under the effect of external magnetic field is built based on magnetohydrodynamics （MHD） equations. By adopting the commercial computational fluid dynamics （CFD） package based on the control-volume method, the above MHD equations are solved. For the media of air-10%PA and air-10%POM, the distributions of stationary temperature and electrical potential and the transient motion processes are compared with those of air arc. The research shows that both air-10%PA and air -10% POM can cool the arc plasma and the former is more effective. Both of them can increase the stationary voltage as well. Moreover, the presence of the two mixtures can accelerate the arc motion toward the quenching area and ensures the arc quenched in time.     

金属相气相分断电弧状态转换机理的研究

电触头是高、低压电器中的关键元件，其性能直接影响到电器运行的可靠性。研究电弧对触头的能量输入和触头的响应具有非常重要的意义。对AgSnO2和AgNi两种触头材料在不同的电压、电流等级下，进行了大量的试验，对直流分断电弧由金属相电弧向气相电弧转换的规律进行了探讨。     

Simulation Research of Magnetic Constriction Effect and Controlling by Axial Magnetic Field of Vacuum Arc

Based on magnetohydrodynamic (MHD) model of vacuum arc, the computer simulation of vacuum arc was carried out in this paper. In the MHD model, mass conservation equation, momentum conservation equations, energy conservation equations, generalized ohm‘s law and Maxwell equation were considered. MHD equations were calculated by numerical method, and the distribution of vacuum arc plasma parameters and current density were obtained. Simulation results showed that the magnetic constriction effect of vacuum arc is primarily caused by the Hall effect. In addition, the inhibition of axial magnetic field (AMF) on constriction of vacuum arc was calculated and analyzed.     

中压开关柜在线监测装置的研制及其抗电磁干扰设计

介绍了用于现场监测中压开关柜的母线温升、绝缘状态、机械特性数据,并通过液晶显示的在线监测装置。该装置利用80C196KC单片机对机械、温度、绝缘传感器传送过来的信号进行采集、处理和分析,并根据用户通过键盘所设定的阈值进行超限报警指示,同时通过RS-485通信接口将数据输送到上位机。针对所研制的监测装置工作环境的电磁干扰问题,讨论了几种软、硬件抗电磁干扰的方法。     

AgMeO材料触头的电弧侵蚀形貌特征

在CKS-1．4kA触头材料自动测试仪上在几百安以下电流对AgMeO材料触头进行了大量分断电流试验，用SEM扫描电镜和光学金相显微镜进行了一系列微观测试拍照，EDAX能谱仪和x射线衍射分析了表面及剖面的元素成分分布，归纳出AgMeO触头材料的五种侵蚀形貌特征，分析了它们对触头工作性能的影响。     

真空断路器机械特性的在线监测方法

研究了真空断路器机械特性的在线监测方法。采用角位移传感器间接测量动触头的行程曲线,有效解决了直线位移传感器安装困难和高电位隔离的问题;通过监测操作过程中的振动信号,得到了在线状态下动静触头的关合和刚分时刻;用霍尔电流传感器监测分合闸线圈电流,配合动触头位移曲线,得到反映真空断路器机械特性的多个特征参量。     

Numerical Study on Arc Plasma Behavior During Arc Commutation Process in Direct Current Circuit Breaker

This paper focuses on the numerical investigation of arc plasma behavior during arc commutation process in a medium-voltage direct current circuit breaker(DCCB) contact system.A three-dimensional magneto-hydrodynamic(MHD) model of air arc plasma in the contact system of a DCCB is developed,based on commercial software FLUENT.Coupled electromagnetic and gas dynamic interactions are considered as usual,and a thin layer of nonlinear electrical resistance elements is used to represent the voltage drop of plasma sheath and the formation of new arc root.The distributions of pressure,temperature,gas flow and current density of arc plasma in arc region are calculated.The simulation results indicate that the pressure distribution related to the contact system has a strong effect on the arc commutation process,arising from the change of electrical conductivity in the arc root region.In DCCB contact system,the pressure of arc root region will be concentrated and higher if the space above the moving contact is enclosed,which is not good for arc root commutation.However,when the region is opened,the pressure distribution would be lower and more evenly,which is favorable for the arc root commutation.     

高气压电弧的状态及其转换

阐明了高气压条件下(1个大气压及以上)电器分断电路过程中金属蒸气态电弧和气体态电弧及其转换这一物理事实;简要论证了电弧状态及其转换对电极材料侵蚀机理、电弧停滞时间和电弧移动特性等科学问题的重要性;较系统地分析了金属蒸气的形成原因和扩散机理。     

基于振动信号小波包提取和短时能量分析的高压断路器合闸同期性的研究

该文提出了一种分析高压断路器合闸同期性的新方法将小波包提取算法和短时能量分析方法相结合，利用小波包分解与重构原理将断路器合闸振动信号分解到不同频段中，并对代表高频冲击信号的分解系数进行重构，然后运用短时能量分析方法对重构后的信号进行分析，辨识出合闸变位点。通过对三相合闸过程的分析，得出三相同期性。通过MATLAB仿真分析和实验结果验证了该方法的有效性。     

真空电弧磁流体动力学模型与仿真研究

以离子与电子的双流体模型以及麦克斯韦方程为基础，推导得到了真空电弧的二维磁流体动力学(MHD)模型。MHD模型中包括质量方程、动量方程、能量方程、麦克斯韦方程和全欧姆定律，通过对这些方程的数值计算，得到了真空电弧等离子体参数与电流密度的分布，文中计算分析了电弧电流、电极间距以及不同分布的纵向磁场对真空电弧等离子体参数与电流密度的影响。