Estimating of current rise time of glow discharge in triode electrode system in case of control pulsing

There are represented relations for approximate estimation of discharge current rise time in triode electrode systems of high-voltage glow discharge in case of applying of control pulses to auxiliary electrode. Theoretical transient analysis of high-voltage glow discharge is based on definition of the anode plasma volume and its ions concentration. Represented calculations show current rise time in real systems of high-voltage glow discharge is from 20 to 250 μs. Obtained results have great practical value for design of cathode-ray equipment.     

大功率CO2激光器脉冲电源研究

本文论述了直流高压与高频脉冲电源相叠加，构成高频、高压脉冲电源，并使其对CO2激光器进行放电实验，研究了同条件下的放电参数与功率。     

Poynting's vector and the wavefronts near a plane conductor

An equation is derived for the time average of Poynting's vector near a plane conductor, which shows that the intensity vector is approximately normal to the wavefronts if one only excludes those regions for which the electric field changes very rapidly in the direction normal to the plane conductor.     

平面放电开关电流波形畸变分析

为了解决电流波形畸变的问题,结合平面放电开关放电后图片,根据导体电爆炸理论对电极烧蚀造成电流波形畸变进行了分析。基于热传导理论,研究了平面放电开关电极在发生弧光放电时的简化数学模型,根据数学模型进行了数值模拟计算,得到了电极的时间温度分布曲线。曲线显示在电流持续时间内电极厚度方向上,温度可以达到10 K量级,电极历经各态相变最终发生爆炸现象,从而导致电流波形发生畸变。根据研究结果,提出解决问题的几种方案。     

The effect of ionizing radiation on the breakdown of large gaps in air

The influence of gamma radiation on the breakdown of a point-plane gap has been studied using impulse voltages of short and long wavefronts. Scatter of breakdown of some gaps is reduced by a factor of two and the mean breakdown value is reduced by a few percent.     

电真空器件管壳耐压特性分析

本文指出了电真空器件的高压放电和击穿类型,真空击穿和沿面闪络的物理机理、影响因素和预防措施.     

A phased-array stimulator system for studying planar and curved cardiac activation wavefronts

Wavefront propagation in cardiac tissue is affected greatly by the geometry of the wavefront. We describe a computer-controlled stimulator system that creates reproducible wavefronts of a predetermined shape and orientation for the investigation of the effects of wavefront geometry. We conducted demonstration experiments on isolated perfused rabbit hearts, which were stained with the voltage-sensitive dye, di-4-ANEPPS. The wavefronts were imaged using a laser and a charge-coupled device (CCD) camera. The stimulator and imaging systems have been used to characterize the relationship between wavefront velocity and fiber orientation. This approach has potential applications in investigating curvature effects, testing numerical models of cardiac tissue, and creating complex wavefronts using one-, two-, or three-dimensional electrode arrays.     

基于超声和LabVIEW局部放电在线监测系统的研制

局部放电是使高压电力设备绝缘损坏的一个重要因素,为确保其安全、可靠运行,对高压电力设备进行在线监测至关重要.该文主要研究开发一种基于超声法和虚拟仪器的局部放电实时在线监测系统,基于4个声发射器检测局部放电源超声波信号,通过时域和频域分析,研究局部放电的超声信号特性,为故障诊断提供数据共享;采用虚拟仪器技术,实现本系统人机界面化,再结合后台数据库,达到多功能、多通道的实时监测.该系统的应用有利于发现绝缘故障的早期征兆,是诊断绝缘故障的一种有效方法.     

干涉型计算机全息图检测非球面

本文从离轴参考束全息图的基本方程出发,介绍了干涉型计算全息图。分析了宽条纹和窄条纹干涉型全息图的特点并给出了检验结果。指出了波差近似计算公式的适用范围。给出了三组实际检验结果。实验表明,(-1,0)和(0, 1)级波面的干涉图是相同的,并给出了解释。     

Solid‐State Electrode Materials with Ionic‐Liquid Properties for Energy Storage: the Lithium Solid‐State Ionic‐Liquid Concept.

Herein, the novel concept of a solid‐state electrode materials with ionic‐liquid (IL) properties is presented. These composite materials are a mixture of electroactive matter, an electronic conductor, a solid‐state ionic conductor and a polymeric binder. The approach of a solid‐state ionic conductor combines the high safety of an IL with the nanoconfinement of such a liquid in a mesoporous silica framework, an ionogel, thus leading to a solid with liquid‐like ionic properties. The same ionic conductor is also used as a solid‐state separator to evaluate the properties of our solid‐state electrode materials in all‐solid‐state batteries. Such a concept of a solid‐state electrode material contributes to addressing the challenge of energy storage, which is one of the major challenges of the 21^st century. The ionogel, along with its processability, allows a single‐step preparation of the assembly of the solid‐state electrode and solid‐electrolyte separator and can be applied without specific adaptation to present, thick electrodes prepared by the widespread tape‐casting technique. The filling of the electrode porosity by an ionogel is shown by elemental mapping using scanning electron microscopy, and is subsequently confirmed by electrochemical measurements. The ionogel approach is successfully applied without specific adaptation to two state‐of‐the‐art, positive electroactive materials developed for future‐generation lithium‐ion batteries, namely LiFePO₄ and LiNi_1/3Mn_1/3Co_1/3O₂.     

100kJ级多路强电脉冲发生装置的同步精度技术研究

本文介绍了＂多路强电（磁）脉冲发生装置＂同步精度研究采用的每路输出＂储能电容＋同轴脉冲大电流火花开关放电＂型高压脉冲形成电路。用同轴电缆作为传输线将工作部件连接起来,以脉冲气体激光器作为终端负载（或其他负载,如磁脉冲线圈、电水锤等）组成多路相互隔离的强电脉冲充放电路,设计采用＂多路高压纳秒脉冲发生器装置＂进行同步精度触发,使高功率气体激光器的放电系统同时获得多路同步输出的高强电脉冲能量进行激励放电。同步精度装置的实验研究结果表明,多路同步导通强电脉冲能量已超出100kJ级,多路触发脉冲同步精度〈10ns,可为脉冲气体激光器提供更加超强激励触发能量获得高功率激光。     

Partial discharge testing of solder fillets on PCBs in a partial vacuum: new experimental results

This work investigates the influence on the partial discharge (PD) onset due to the geometry of solder fillets of aerospace and spacecraft component assemblies operating in vacuum and at high voltages. An automatic measuring system has been developed and calibrated to detect PD signals in vacuum (proportional to the apparent charge) which are recorded and displayed in terms of amplitude and temporal distributions. The experimental part of the project is aimed at investigating the influence of the geometry of solder fillets (produced according to the European space industry standard, ECSS-Q-70-08), on the occurrence of PD activity. Stranded terminals of high voltage cables were soldered to circular copper pads on FR4 fiberglass epoxy printed circuit board (PCB). Various copper electrode configurations have been produced and, prior to the test program, they were characterized for dimensional, electrical and optical properties. Two types of solder fillet geometries have been realized for each electrode configuration: round joints with an abundance of solder and sharp pointed joints made with minimal solder. The minimum distance between electrodes for all samples is nominally 5 mm. Paschen-like curves were established from measurements performed where the product of pressure x distance lies in the range of 2 mbar mm-50 mbar mm. Corona inception voltage (CIV) and corona extinction voltage (CEV) values were recorded at different values of pressure x distance. Stable glow discharge triggering voltage and current were also measured. The experimental results indicated that the PD activity for the sharp pointed pads and sharp pointed joints is greater than the other cases, but no significant differences (less than 50 V) of the values of CIV and CEV have been found.     

基站与高压电力塔共站的防护分析

随着5G通信技术的发展,5G基站对站点数量的需求越来越大,将电力塔与通信基站结合,是5G基站建设的趋势.但是,基站与高压电力塔共站时需要做好高压电力线对基站的危险影响防护,尤其要关注高压电力线故障时地电位反击对基站及附近居民的影响.从高压电力线对基站的容性耦合、感性耦合和阻性耦合做了分析,并分别从电气安全隔距、导线布置...     

适合微细电火花加工的新型压电陶瓷驱动电路

设计并研制了一种新型压电陶瓷驱动电路。该电路采用高压直流放大器加功率放大器原理,具有良好的动态响应性能。在加工过程中,工具电极不仅可以实现常规的进给与回退,还可以实现振动式进给,以利于蚀除产物的排出,改善电火花加工的间隙状态。     

接地体附近导体对土壤中冲击电势分布的影响

模拟实际冲击接地实验的构架,采用时域有限差分(FDTD)方法建立计算模型,计算了雷电流冲击下接地体附近土壤中的冲击电势分布情况。计算结果表明:接地体周围土壤中存在的其它金属导体,将改变土壤中的电势分布,导致附近导体与接地体之间的电位差增大,而且,该电位差随土壤电阻率的增大而增大,与附近导体的形状体积也有关。接地体周围土壤中其它金属导体可能使得在所谓的安全距离上的安全裕量减少。     

Double snapback characteristics in high-voltage nMOSFETs and the impact to on-chip ESD protection design

The double snapback characteristic in the high-voltage nMOSFET under transmission line pulsing stress is found. The physical mechanism of double snapback phenomenon in the high-voltage nMOSFET is investigated by device simulation. With double snapback characteristic in high-voltage nMOSFET, the holding voltage of the high-voltage nMOSFET in snapback breakdown condition has been found to be much smaller than the power supply voltage. Such characteristic will cause the high-voltage CMOS ICs susceptible to the latchup-like danger in the real system applications, especially while the high-voltage nMOSFET is used in the power-rail electrostatic discharge clamp circuit.     

220kV高压输电线路导线架设施工方法及技术要点分析

本文主要对高压输电线路导线架设施工以及线路改造中的相关技术要点进行简要说明,望能够促进高压输电导线施工技术的发展与进步.     

Electrostrictive Mechanism of Liquid Breakdown in Strongly Nonhomogeneous Field under the Action of Nanosecond Voltage Pulse

Electrostriction mechanism of breakdown in polar liquid caused by high-voltage nanosecond pulse is studied. Nonstationary motion of liquid in the pin-to-plane system exposed to a pulse with peak voltage of 30 kV and 6-ns duration is numerically analyzed. Cavities in which the breakdown can be initiated are formed in the vicinity of the tip electrode. Dimensions of such cavities are estimated, and the conditions for formation are formulated. Profiles of voltage and current pulses are measured for breakdown in water and air. The velocity of breakdown development in air is determined using the time delay of the pulse measured by the shunt of discharge current at several interelectrode distances. The proposed method has limitations in the measurement of breakdown in water due to the effect of displacement current that exceeds the discharge current.     

Enhanced Cycle Stability of Low-Cost Na-Rich Metallic NaCl Electrode for Advanced Na-Ion Batteries

Sodium-rich metallic Na_x+z has received significant attention as a low-cost alternative to the conventional electrode materials used in Li-ion batteries. However, the poor cyclability of Na_xCl remains a major challenge to its practical application. Here, a simple method is developed for improving the electrochemical performance of Na_xCl by controlling the upper limit of cut-off voltage. It is demonstrated that additional Na-vacancy defects can be introduced in the NaCl structure during the high-voltage activation process at 4.5 V. The structure then accommodates more sodium ions during the next discharge, resulting in increased capacity. At the same time, Cl-ions released by NaCl decomposition are oxidized to form Cl-based organic species at the active material interfaces. This plays a crucial role in protecting the NaCl electrode from undesired side reactions at high voltage. In short, this control of the charging protocol helps to induce more vacancies in the NaCl structure, as well as form stable interphases on the electrode surface, contributing to the increased capacity and enhanced cycle stability. This study will help in exploring a new approach for developing low-cost and high-capacity electrode material, which can potentially be applied in future energy-storage systems.     

低抖动Marx型触发源系统设计与实验

设计了一套具有低输出抖动的小型Marx型触发源系统。将充电、触发电源等进行了整体集成,结合高储能密度的四端型薄膜电容器设计,实现了系统的紧凑化,体积仅0.20 m3。将场畸变气体开关电极设计为环形轨道状,采用平面触发方式,以利于开关的低抖动输出和稳定工作。该系统输出电压、工作频率分别在10~90 kV,1~30 Hz范围内独立可调。以30 Hz重复频率工作300次,输出抖动的最大偏差(极差)仅为13.0 ns。相比30 Hz、30次结果,工作时间延长了9倍,输出抖动极差仅增加了38%,表现出极低的输出抖动和高的稳定性,是一种理想的高压触发源系统。