特高压屏蔽测试大厅弱电抗干扰施工原理与工艺

2000k V交流特高压屏蔽测试大厅是利用电磁屏蔽原理,在其内部进行特高压设备研发测试的工艺装置。在测试过程中,存在电晕放电,特高压交变电磁场干扰。弱电集成研究在监控大厅内用屏蔽技术消除辐射干扰及穿越屏蔽层消除、抑制传导干扰方法。屏蔽效能列线图验算,解决了屏蔽效能的工程验算;截止波导管的概念及工程验算,滤波器安装,光纤应用,接地介绍了传导干扰抑制方法。高速球防浪涌设计,屏蔽网线、机柜及门禁系统安装介绍了屏蔽的应用实例。期待对EHV环境弱电施工提供工程借鉴。     

浪涌保护器原理分析

对浪涌保护器的作用、构成、主要器件的特点进行阐述,结合实际应用的DX发射机浪涌抑制器原理进行了分析,并在实际处理故障时得以应用。     

移动通信基站的防雷与接地

通过对全国十几年省份移动通信基站遭雷击情况统计分析，表明了移动通信基站雷电过电压保护的重要性。从移动通信基站的事故分析入手，着重论述移动通信基站的雷击概率，雷塌过电压保护的要求及接地体的选择。     

双层电视信号处理板设计概要

分析和总结了量产机芯8K(MTK)、8M(MSTAR)、8R(REALTEK)系列等多个机芯在设计、调试、生产和市场反馈等多阶段出现的问题,从热设计、信号串扰、信号完整性、ESD、雷击多个方面阐述了双层信号处理板设计的常见设计缺陷和设计误区。该设计以提高双层板设计可靠性和设计成功率为目的,较为有效地从源端对双层板信号设计进行了规范。     

通信机房设备直流电源端口电压瞬变防护

直流电源端口的电压瞬变会导致通信现场设备退出服务。文章比较了美标、欧标和国标相关的规范要求。根据实践经验给出了现场工程实施方面的一些建议。     

基于PDP驱动技术的行扫描芯片浪涌电压抑制方法

分析了等离子体显示器中行扫描芯片的浪涌电压产生机理。结合浪涌电压产生机理从PDP驱动技术的角度提出抑制浪涌电压的理论方案,并以实验室PDP模组为实验载体,通过修改控制板驱动代码来实现该方案。通过实测新方案的波形,并观察PDP屏显示的静态图像与动态图像,验证了该方案可以有效抑制行扫描芯片的浪涌电压。该方案使得芯片的制造成本降低,从而缩减了整个PDP系统的成本。     

浪涌发生器的波形参数的理论计算和实测值

通过电路分析,理论计算出某浪涌发生器的波形参数,并且采用实测波形参数来证实该理论计算方法的正确性。     

非匹配传输线产生宽谱脉冲实验研究

介绍了基于短路开关-锐化开关组合的非匹配传输线的工作原理,通过数值模拟分析了开关的导通时间、导通延时以及形成线的长度对输出宽谱振荡脉冲的影响。设计了非匹配传输线的实验装置并在500kV Marx发生器上开展了实验研究。在短路开关间距为4mm、腔体内充入SF6气体的压力为1.15MPa,锐化开关间距为2.5mm、腔体内SF6气体的压力为1.0MPa的条件下,在50Ω传输线上测得的峰值功率为3.3GW,振荡脉冲的中心频率为169MHz,百分比带宽为22.9%。     

高功率半导体量子阱激光器测试中的突变性损伤

在使用综合参数测试仪测试808nm发射的半导体量子阱激光器的过程中，出现了一种由电浪涌所导致的灾变性损伤。通过测试的功率曲线和伏安特性曲线，断定激光器出现了突变性的损伤，同时测试的发射光谱不再是激射光谱，而是由自发辐射所产生的荧光光谱。由扫描电镜（SEM）观察到了激光器的腔面膜出现了熔化，证实激光器的确发生了灾变性损伤。作为对比，我们引用了另一种在测试中发现的快速退化现象，对两种退化出现的原因进行了理论上的分析，了解到激光器的退化主要还是由器件本身的材料、结构以及后期的工艺过程所决定的，在测试器件过程中电浪涌不只不过会加速或产生突然灾变性退化。通过测试我们建立了一种比较简单的检验一个激光器质量可靠性的方法，所以理解由电浪涌所引起的退化行为是非常重要的。     

Long-term deconditioning of gas-filled surge arresters

The aim of this paper is to identify parameters that influence the long-term deconditioning effect of gas-filled surge arrester (GFSA) and to provide practical recommendations for mitigating this effect. Namely, after some period of time, on order of hours or days, during which there is no activation due to overvoltage, the deconditioning of GFSA occurs. This effect was observed experimentally within the paper. The observed parameters that could influence the long-term deconditioning effect were the following: shape of voltage load, gas type, gas pressure, interelectrode distance, electrode material, electrode surface topography as well as GFSA design such as two- or three-electrode configuration. According to the results obtained, it has been shown that the occurrence of long-term deconditioning in an insulating system, insulated by a noble gas at a subpressure and with small interelectrode distances, is a phenomenon that always occurs when the insulating system is at rest for about an hour. It has been found that the type of noble gas does not influence the long-term deconditioning. Analysis of such insulating systems' parameters, with a prospect of being used as GFSAs, has demonstrated that this phenomenon is less pronounced at higher pressures (for the same value of the pressure (p) and interelectrode distance (d) product) and for electrodes with microscopically embossed surfaces. According to the results that were obtained by noble gases and their mixtures, as well as the results that were obtained by mixtures of SF6 gas with noble gasses, it can be claimed with confidence that the effect of the long-term deconditioning is an electrode effect. It has also been established that the deconditioning effect does not depend on the electrode material except in the case of electrodes made out of noble metals, which reduce the effect. Based on these results, it can be recommended that the working point of GFSAs be set (according to the DC breakdown voltage value) at a pressure that is as high as possible (with pd?=?const), and that the electrode active surface should have a marked microscopic topography. In addition to this, an essential conclusion for GFSA manufacturers is that long-term system deconditioning is caused by impurities and adsorbed gases that appear at electrode during the state of rest. Out of these two causes, the influence of impurities is probably the dominant one, which is proved by considerably reduced long-term deconditioning in the case of noble metal electrodes, not susceptible to corrosion. This has also been confirmed by a less distinct effect of long-term deconditioning in the case of sandblasted electrodes that have a stronger tendency towards gas adsorption and a weaker tendency towards corrosion. However, it has been shown that adding of the third electrode (that is concentric to the main electrode system) on a free floating potential along with usage of sandblasted electrodes and with smaller interelectrode distance significantly reduces the effects of the long-term deconditioning.