电涌保护器应用中的几个问题

探讨了电涌保护器(SPD)应用中的4个颇有争议的问题，这就是SPD的响应时间、多级SPD的动作顺序、不同波形中冲击电流的等效变换以及SPD的残压与冲击电流峰值的关系，最后说明了SPD应用中各电压之间的相互关系。     

电涌保护器选型问题分析

简单介绍了电涌保护器(SPD)目前使用中存在的问题;依据相关防雷技术规范,结合SPD自身的最大持续运行电压、电压保护水平、冲击电流、标称放电电流等四个参数探讨了SPD的合理选型问题;强调SPD必须被保护设备相匹配,才能真正实现其保护价值。     

浅谈电涌保护器的防雷接地与应用

雷电引起的冲击过电压和电流成为造成电气设备损坏和工作中断的主要因素之一,电涌保护器SPD是电子设备雷电防护中不可缺少的一种装置。文中介绍SPD的分类、主要参数、选择和安装、通流能力的选择、选择的五个原则、SPD的保护和后备保护元件的选择等,SPD设计的合理与否,对电气设备的安全使用与运行有着至关重要的作用。     

过流过压一体化电涌保护器在大电流（8/20 μs）冲击下稳定性研究

阐述了过流过压一体化电涌保护器（SPD）的工作原理,介绍了相关标准对SPD过电流保护性能要求的规．详细论述了三种大电流冲击下过电流保护装置方案的稳定性研究,通过试验数据和结果对比分析了三种方案的优．     

限压型低压电涌保护器级间配合研究

采用电磁暂态程序(EMTP)仿真方法,研究了MOV限压型低压电涌保护器(SPD)两级保护电路.模型中采用传输线模型仿真电缆线,通过实验测量SPD在不同冲击电流下的残压值获得SPD仿真的必要电流和残压值参数.得到了两级在不同冲击电流大小、线缆长度连接时的电流分布情况和残压大小.对传输线的长度为5、10、20 m,冲击电流为8.9 kA时的仿真结果进行实验验证,实验结果和仿真结果基本一致.该项研究有助于雷电防护中SPD辅助工程设计.     

浪涌保护器冲击电流自动测试系统

针对浪涌保护器(SPD)带电试验的冲击电流试验的特点,研制了一种体积小、耐冲击电流能力强的耦合与去耦网络(CDN),它和冲击电流发生器、PLC、可控开关、相位跟踪电路及数字峰值电压表一起组成SPD冲击电流自动测试系统。通过所研制的CDN供电电源,该系统可对SPD进行共模和差模试验,其冲击幅值可高达100kA。     

开关型SPD在不同冲击电流下的工频续流实验研究

研究了冲击电流波形对开关型电涌保护器（SPD）的工频续流的影响。设计了冲击电流与工频电源试验回路,采用8／20us和10／350us冲击电流波形,从0°同步触发角开始,以30°的间隔逐级增加,对该SPD的工频续流进行对比试验。试验结果表明,采用10／350us冲击电流作为Ⅰ级开关型SPD试品动作负载预处理试验的测试波形,对试品的考验比采用8／20us冲击电流更严苛。     

配电浪涌保护器在多波形多脉冲电流下的耐受特性

采用MWMPC(多波形多脉冲电流)来模拟真实雷电流,研究了不同冲击电流幅值、多脉冲时序和时间间隔对试验结果的影响,分析了Ⅰ级SPD(浪涌保护器)阀片在MWMPC下耐受性能的影响因素,并与传统测试电流下的阀片耐受试验结果进行对比。研究结果表明:标准测试电流无法模拟实际多重雷电流作用在SPD上的强劣化效果;SPD阀片在MWMPC下的损坏形式是涂层裂缝、穿孔以及一种特有的裂面上可见穿孔痕迹的炸裂;增加脉冲电流幅值、缩短多脉冲电流的时间间隔或当回击间持续电流出现在后续回击电流之间时,阀片更容易损坏;在携带大能量的冲击电流下,SPD阀片的涂层会影响散热,使阀片的耐受性能不如ZnO裸片好;而当冲击电流波形较陡或者幅值很大时,ZnO裸片容易发生表面闪络,其耐受高陡度冲击电流的能力不如带有涂层的SPD阀片。     

电涌保护器老化研究的回顾与进展

电涌保护器(surge protection device)是一种保护装置,对保护电子设备起到至关重要的作用.它能把电子设备中的过电压控制在可承受的范围内,还能抵御冲击电流的冲击,防止电子设备因此而发生损坏.长期工作电压的积累或者短时冲击电流的冲击,SPD不可避免地会发生老化现象,若发现不及时,会对设备产生严重后果.归纳分析了中外学者对SPD老化机理的观点及实验进展,SPD老化程度的检测以及加强SPD稳定性能的手段.     

电涌保护器的应用与金山花园信息系统防雷设计

通过对国际标准IEC61643和国家标准GB50057-94《建筑物防雷设计规范》(2000年版)的研究,探讨了电涌保护器(SPD)在智能建筑安全设计中要考虑的若干问题。并通过工程实例,分析电涌保护器若干技术参数与设计选用要点,给出SPD的残压与冲击电流峰值的关系及各级电涌保护器具体选用时电压之间的配合关系。     

电涌保护技术讲座第六讲电源电涌保护器的布局

说明建筑物中电涌保护对象的确定,电源侧SPD布局和配置、配合的原则,典型布局方案.简要介绍了几个典型的方案.     

线路电阻对SPD配合的影响分析

为了准确分析用于低压配电系统过电压防护的多级浪涌保护器(SPD)的配合问题,通过建立SPD配合电路的拉氏运算方程,求解并分析线路电压降的解析解,理论研究了线路电阻对低压系统SPD配合的影响,指出忽略线路电阻将使通过后级SPD的电流被夸大,造成配合分析的不准确。理论分析表明,在前级SPD的残压一定的情况下,2级SPD间的电压差主要由后级SPD的V-I特性曲线、线路电感和线路电阻共同决定。通过对多种线路模型的SPD配合进行仿真计算,验证了理论分析的正确性。     

电磁瞬态多级防护技术研究

对电磁瞬态 (电涌 )的器件防护技术进行了研究。根据电涌多级防护的基本要求 ,利用电路波过程理论 ,推导了两级防护电路的电压和电流波的计算公式。在此基础上 ,对两级防护的动态特性进行计算分析。最后采用 EMTP软件对多级防护的实例进行仿真     

多分支系统中SPD配合的研究

通过理论分析和软件仿真,研究了低电压系统中多分支电路对开关型SPD和限压型SPD之间的配合,及限压型SPD间配合的不同影响.研究表明,各支路波阻抗的并联效果有利于设备的保护,使MOV型SPD间的配合效果提高,但开关型和MOV型SPD配合时,易造成开关型SPD不动作,在工程实践中应予注意.     

Effective Protection Distances of Low-Voltage SPD With Different Voltage Protection Levels

If surge protection devices (SPDs) are installed without consideration of the concept of lightning protection zones, the equipment to be protected might be damaged despite the correct energy coordination of SPDs. This damage is induced by the reflection phenomena on the cable connecting an external SPD and the load protected. These reflection phenomena depend on the characteristics of the output of the external SPD, the input of the loads, and the cables between the load and the external SPD. Therefore, the SPD has an effective protection distance under the condition of the specific load and the specific voltage protection level of SPD. In this paper, the equipment with different load characteristics and SPDs with different voltage protection levels are analyzed combinatorially under the operation of the surge combination wave. The influence of voltage protection level on the effective protection distance is discussed. Moreover, the effective protection distance of the SPD with the same parameter in a different voltage protection level is also analyzed in detail. The analyzed results show that the effective protection distance would be very long if the impedance of equipment is close to or smaller than the characteristic impedance of the connecting cable.     

A study of modeling of EMTP analysis for indoor distribution line

Damage to home electric appliances due to lightning surges has recently become more common. The installation of SPDs (surge protective devices) in interior wiring is a countermeasure against damage and is also becoming more widespread after amendment of the regulation on indoor wires in 2005. Past study showed an effective method in which the earth line of the SPD is connected with that of home appliances and is grounded at one place in the home. However, because the methods of installing the distribution line in homes vary, it is difficult to estimate the effect of SPDs in every home, and high‐precision analysis by EMTP for interior wiring and SPD in the home is required. In this study, experiments were conducted with interior wiring and varistors, which constitute SPDs, and this paper reports the results of those experiments and of EMTP analytical models. © 2011 Wiley Periodicals, Inc. Electr Eng Jpn, 175(4): 24–33, 2011; Published online in Wiley Online Library ( wileyonlinelibrary.com ). DOI 10.1002/eej.21062     

A low‐loss snubber for reducing motor terminal surge voltage

The development of an advanced Insulated Gate Bipolar Transistor (IGBT) has enabled high‐frequency switching operation and has improved the performance of PWM inverters for motor drive. However, the IGBT's high rate of dv/dt has adverse effects on motor insulation stress. In many motor drive applications, the inverter and motor are separated, requiring long motor feeds. The long cable contributes high‐frequency ringing at the motor terminal and results in high surge voltage which stresses the motor insulation. The inverter output filter and RDC snubber are the conventional method for reducing the surge voltage. In this paper, we propose a new low‐loss snubber to reduce the motor terminal surge voltage. The snubber consists of the series connection of chraging/discharging capacitor and the voltage‐clamped capacitor. At IGBT turn‐off, the snubber starts to operate when the IGBT voltage reaches the voltage‐clamped level. Since dv/dt is decreased by snubber operating, the peak level of the surge voltage can be reduced. Also the snubber operates at the IGBT voltage above the voltage‐clamped level, and the snubber loss is largely reduced compared with the RDC snubber. The proposed snubber enables reduction of the motor terminal surge voltage with low loss. © 2005 Wiley Periodicals, Inc. Electr Eng Jpn, 150(4): 64–72, 2005; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/eej.10378     

Evaluation of the effective protection distance of low-voltage SPD to equipment

Installing surge protection devices for a low-voltage power supply is important to ensure the survival of electric or electronic devices and systems. Sometimes one group of surge protective devices (SPDs) installed on the distribution board is expected to protect all equipment supplied power by this distribution board. This equipment is connected to the distribution board by cables with different lengths, the influence of the cable length between the SPD and protected equipment on protective effects of SPD was discussed. The reflection and oscillation phenomena of the transient voltage caused by the connecting cables were analyzed, which would affect the protective effects of SPDs. These phenomena depend on the characteristics of the SPDs, the properties of the protected loads, and the length of the connecting cable. Five different types of loads and three different cable lengths have been simulated by electromagnetic transient analysis software, and their respective transient voltages across the SPD and the load were discussed in detail. The effective protection distances of SPD to equipment were analyzed for different types of loads.     

便携式SPD测试仪组合波发生器的仿真与试验

为检测现场用电涌保护器是否损坏、老化,通常要测量直流1mA电压.泄漏电流以及冲击组合波下的SPD动作特性[1].本文通过电路参数计算和EMTP-ATP仿真电路元件对输出波形的影响,得出了波头时间主要由电感决定,波尾时间主要由电容量和放电回路的总等效阻抗决定.并在此基础上研制出最大幅值为6kV/3kA的冲击组合波发生器....     

高压电缆冲击特性长度计算研究

介绍了规程及典型设计中电气设施的绝缘特性、保护措施的有关规定,对高压电缆输电线路系统中电缆冲击特性长度概念进行了阐述,给出了冲击特性长度的计算公式,并用实例验证了公式的合理性与正确性,指出应针对不同的工程条件计算高压电缆的冲击特性长度,当电缆的实际长度小于冲击特性长度时,合理确定高压电缆的雷电冲击耐受电压峰值,并在电缆线路两端分别装设避雷器。