第十九届国际真空放电及绝缘会议将于2000年9月西安交通大学召开

<正> 第19届国际真空放电及绝缘会议(9th Intemational Symposiu on Discharges and Electrical Insulation in Vacu-um,简称ISDEIV 2000)将于2000年9月18～22日,在我国西安交通大学召开.这是该国际学术会议首次在我国、也是首次在亚洲召开.ISDEIV是一个专门研究和交流真空放电和绝缘(包括真空电弧、真空开关)等方面前沿课题的非盈利的国际学术性组织,于1964年在美国成立,其宗旨是促进真空放电及绝缘科学和应用的发展,主要通过举办国际会议进行学术交流.     

基于真实气体模型的SF6断路器中冷态气流场特性的仿真分析

准确地计算灭弧室内气流场特性对于SF6断路器优化设计有重要意义。基于真实气体模型(user-defined real gas model,UDRGM),运用线性插值与UDRGM相结合的方法来导入SF6的气体属性,并与流场控制方程组联合求解,研究了SF6断路器简化灭弧室冷态气流场的特性规律。通过分析监测点处的物理量发现,触头分开过程中,灭弧室内整体压力差不断增加,气体密度分布主要取决于气压的变化;在喷口区域,气压最大值出现在动触头端部中心位置,各监测点处的气压与马赫数受触头位置的影响较大,当触头运动到监测点时,马赫数与气压会发生跃变,而喷口内部两触头间的气压变化梯度却很小。结果表明,基于UDRGM建立的SF6断路器冷态气流场分析新方法可有效地提高计算精度,也为热态气流场的研究提供了基础。     

现场可编程门阵列在开关设备在线监测中的应用

利用现场可编程门阵列可靠性高、通用性强、可重构等优点,设计出用于开关设备状态在线监测的专用芯片。该芯片集采集、计量、通讯、报警功能于一体,配以少量的外围器件,便可实时监测开关设备的温度、机械、绝缘等各项状态参数。该芯片具有通用的通讯接口,可以与上位机通讯。与以往使用单片机实现开关设备状态在线监测的设计方案相比,该设计具有可重构、速度快、灵活性高的特点。     

基于快速ICCD照相、纹影照相及发射光谱法的激光诱导等离子体特性(英文)

Pulsed laser produced plasmas(LPP)are important for industrial applications and fundamental researches,and their complex,multi-physical and cross-chemical processes need to be investigated more comprehensively.In this work,images of the luminous plasma,the spatial density distribution,and the plasma parameters are experimentally investigated by using fast ICCD photography,schlieren photography,and optical emission spectroscopy.Plasmas are produced by a 1 064 nm,15 ns Nd:YAG laser.Free expanding and splitting phenomena are observed in vacuum(at the pressure of about 1×10 3Pa)and air(at the pressure of 20 Pa)using fast photography,respectively.Meanwhile,shock waves formed in the atmospheric laser produced plasma are visualized by schlieren photography.The formation of shock waves is interpreted with the Sedov-Taylor theory,and an averaged expansion velocity about 375 m/s of the shock waves is estimated during 200～1 000 ns.Atmospheric air is found to have significant confinement effects on the plasma expansions compared to that in vacuum or low pressure ambient.Based on the optical emission spectroscopy,after 1 000 ns,at 0.6 mm above the target,the plasma temperature is about 7 800 K and the electron number density is approximately 0.64×1016cm-3.     

专栏评述：面向双碳目标的环保型电力设备

习近平总书记在第七十五届联合国大会一般性辩论上向全世界作出“碳达峰”、“碳中和”的庄严承诺,我国成为全球气候治理、实现绿色低碳发展的重要参与者、贡献者和引领者,同时也必将经历一场艰巨的转型之路。我国电力系统碳排放占到了碳排放总量的40%,因此“碳达峰”、“碳中和”目标的提出对于构建深度无碳化电力系统提出了新要求。为了顺应时代发展潮流,积极响应国家重大战略,助力顺利达成“碳达峰”、“碳中和”目标,构建技术先进、环境友好的深度低碳电力系统,发展环保型电力设备具有重要意义。     

金属丝尺寸对单丝电爆炸能量沉积阶段影响的数值模拟研究（英文）

The initial stage of wire array Z-pinch,i.e.the energy deposition stage in single wire electrical explosion,plays a very important role in the performance of the whole Z-pinch process.In this paper,this stage was modeled and simulated.Based on a mathematic model coupled with external circuit,the influence of wire dimension on the waveforms of current and voltage and the voltage-peak time in the energy deposition stage was studied.The calculated specific power indicates that time of the energy deposition extends with wire length quadratically.For normal wire dimension of wire array Z-pinch,the energy deposition time decreases slowly with the decreasing wire diameter,until approaches a minimum depended on the wire length.     

Simulation of Vacuum Arc Characteristics Under Four Kinds of Axial Magnetic Fields and Comparison with Experimental Results

Based on a two-dimensional axisymmetric magnetohydrodynamic （MHD） model, the vacuum arc characteristics under four kinds of axial magnetic fields （AMFs） are ana...     

Numerical Simulation of High-Current Vacuum Arc with Consideration of Anode Vapor

A high-current vacuum arc (HCVA) with the consideration of anode vapor is mod-eled and simulated. First, from the HCVA column model, the heat flux density to the anode is obtained, which is put into the anode activity model, and the parameter distributions (such as the vapor temperature and velocity) of anode vapor are obtained from the simulation results of the anode activity model. Then, by iterating and calculating the HCVA column model and anode activity model, the interaction between the HCVA column and the anode vapor is simulated and analyzed. In the simulation, the distribution of the axial magnetic field (AMF) generated by the electrode system is calculated by software ANSYS. The simulation results show that the influence of anode vapor on the parameter distributions in the arc column is significant. The simulation results are also compared with the vacuum arc photograph.     

真空电弧重熔法制造CuCr触头材料

介绍了用真空电弧重熔法制造CuCr触头材料的原理、重熔炉的结构和控制电弧长度的几种方法、在重熔制造过程中对真空度的要求和自耗电极参数的选择以及重熔法的优点和缺点,最后还阐述了利造CuCr合金触头材料的过程和应用范围。     

一种高开断能力两级纵向磁场电极结构的真空灭弧室

设计了一种两级纵向磁场电机结构的真空灭弧室，对其三维磁场颁地计算分析，并将这种电极结构进行了装管试验，试验表明这种电极结构在燃烧弧期间的电弧电压降低，它的开断能力与其他结构相比有大幅度提高。