10kv配电线路防雷外文文献.doc

西安科技大学毕业设计(论文)英文翻译 题 目 柠条塔煤矿10kV配电线路防雷研究 院、系(部) 电气与控制工程学院 专业及班级 电气工程及其自动化0802班 姓 名 关斌斌（0806060209） 指 导 教 师 李 忠 日 期 2012年6月10日_ 英文资料（一）Fundamentals of Lightning ProtectionIntroductionLightning is a capricious, random and unpredictable event. Its physical characteristics include current levels sometimes in excess of 400 kA, temperatures to 50,000 degrees F., and speeds approaching one third the speed of light. Globally, some 2000 on-going thunderstorms cause about 100 lightning strikes to earth each second. USA insurance company information shows one homeowners damage claim for every 57 lightning strikes. Data about commercial, government, and industrial lightning-caused losses is not available. Annually in the USA lightning causes more than 26,000 fires with damage to property (NLSI estimates) in excess of $5-6 billion.The phenomenology of lightning strikes to earth, as presently understood, follows an approximate behavior:1. The downward Leaders from a thundercloud pulse towards earth seeking out active electrical ground targets.2. Ground-based objects (fences, trees, blades of grass, corners of buildings, people, lightning rods, etc., etc.) emit varying degrees of electric activity during this event. Upward Streamers are launched from some of these objects. A few tens of meters off the ground, a collection zone is established according to the intensified local electrical field.3. Some Leader(s) likely will connect with some Streamer(s). Then, the switch is closed and the current flows. We see lightning.Lightning effects can be direct and/or indirect. Direct effects are from resistive (ohmic) heating, arcing and burning. Indirect effects are more probable. They include capacitive, inductive and magnetic behavior. Lightning prevention or protection (in an absolute sense) is impossible. A diminution of its consequences, together with incremental safety improvements, can be obtained by the use of a holistic or systematic hazard mitigation approach, described below in generic terms.Lightning RodsIn Franklins day, lightning rods conducted current away from buildings to earth. Lightning rods, now known as air terminals, are believed to send Streamers upward at varying distances and times according to shape, height and other factors. Different designs of air terminals may be employed according to different protection requirements. For example, the utility industry prefers overhead shielding wires for electrical substations. In some cases, no use whatsoever of air terminals is appropriate (example: munitions bunkers). Air terminals do not provide for safety to modern electronics within structures.Air terminal design may alter Streamer behavior. In equivalent e-fields, a blunt pointed rod is seen to behave differently than a sharp pointed rod. Faraday Cage and overhead shield designs produce yet other effects. Air terminal design and performance is a controversial and unresolved issue. Commercial claims of the elimination of lightning deserve a skeptical reception. Further research and testing is on-going in order to understand more fully the behavior of various air terminals.Downconductors, Bonding and ShieldingDownconductors should be installed in a safe manner through a known route, outside of the structure. They should not be painted, since this will increase impedance. Gradual bends (min. eight inch radius) should be adopted to avoid flashover problems. Building steel may be used in place of downconductors where practical as a beneficial part of the earth electrode subsystem.Bonding assures that all metal masses are at the same electrical potential. All metallic conductors entering structures (AC power, gas and water pipes, signal lines, HVAC ducting, conduits, railroad tracks, overhead bridge cranes, etc.) should be integrated electrically to the earth electrode subsystem. Connector bonding should be thermal, not mechanical. Mechanical bonds are subject to corrosion and physical damage. Frequent inspection and ohmic resistance measuring of compression and mechanical connectors is recommended.Shielding is an additional line of defense against induced effects. It prevents the higher frequency electromagnetic noise from interfering with the desired signal. It is accomplished by isolation of the signal wires from the source of noise.GroundingThe grounding system must address low earth impedance as well as low resistance. A spectral study of lightnings typical impulse reveals both a high and a low frequency content. The high frequency is associated with an extremely fast rising front on the order of 10 microseconds to peak current. The lower frequency component resides in the long, high energy tail or follow-on current in the impulse. The grounding system appears to the lightning impulse as a transmission line where wave propagation theory applies.A single point grounding system is achieved when all equipment within the structure(s) are connected to a master bus bar which in turn is bonded to the external grounding system at one point only. Earth loops and differential rise times must be avoided. The grounding system should be designed to reduce ac impedance and dc resistance. The shape and dimension of the earth termination system is more important a specific value of the earth electrode. The use of counterpoise or crows foot radial techniques can lower impedance as they allow lightning energy to diverge as each buried conductor shares voltage gradients. Ground rings around structures are useful. They should be connected to the facility ground. Exothermic (welded) connectors are recommended in all circumstances.Cathodic reactance should be considered during the site analysis phase. Man-made earth additives and backfills are useful in difficult soils circumstances: they should be considered on a case-by-case basis where lowering grounding impedances are difficult an/or expensive by traditional means. Regular physical inspections and testing should be a part of an established preventive maintenance program.Transients and SurgesOrdinary fuses and circuit breakers are not capable of dealing with lightning-induced transients. Lightning protection equipment may shunt current, block energy from traveling down the wire, filter certain frequencies, clamp voltage levels, or perform a combination of these tasks. Voltage clamping devices capable of handling extremely high amperages of the surge, as well as reducing the extremely fast rising edge (dv/dt and di/dt) of the transient are recommended. Adopting a fortress defense against surges is prudent: protect the main panel (AC power) entry; protect all relevant secondary distribution panels; protect all valuable plug-in devices such as process control instrumentation, computers, printers, fire alarms, data recording & SCADA equipment, etc. Further, protect incoming and outgoing data and signal lines. Protect electric devices which serve the primary asset such as well heads, remote security alarms, CCTV cameras, high mast lighting, etc. HVAC vents which penetrate one structure from another should not be ignored as possible troublesome electrical pathways.Surge suppressors should be installed with minimum lead lengths to their respective panels. Under fast rise time conditions, cable inductance becomes important and high transient voltages can be developed across long leads.In all instances, use high quality, high speed, self-diagnosing protective components. Transient limiting devices may use a combination of arc gap diverters-metal oxide varistor-silicon avalanche diode technologies. Hybrid devices, using a combination of these technologies, are preferred. Know your clamping voltage requirements. Confirm that your vendors products have been tested to rigid ANSI/IEEE/ISO9000 test standards. Avoid low-priced, bargain products which proliferate the market (caveat emptor).DetectionLightning detectors, available at differing costs and technologies, sometimes are useful to provide early warning. An interesting application is when they are used to disconnect from AC line power and to engage standby power, before the arrival of lightning. Users should beware of over-confidence in such equipment which is not perfect and does not always acquire all lightning data.EducationLightning safety should be practiced by all people during thunderstorms. Preparedness includes: get indoors or in a car; avoid water and all metal objects; get off the high ground; avoid solitary trees; stay off the telephone. If caught outdoors during nearby lightning, adopt the Lightning Safety Position (LSP). LSP means staying away from other people, taking off all metal objects, crouching with feet together, head bowed, and placing hands on ears to reduce acoustic shock.Measuring lightnings distance is easy. Use the Flash/Bang (F/B) technique. For every count of five from the time of seeing the lightning stroke to hearing the associated thunder, lightning is one mile away. A F/B of 10 = 2 miles; a F/B of 20 = 4 miles, etc. Since the distance from Strike A to Strike B to Strike C can be as much as 5-8 miles. Be conservative and suspend activities when you first hear thunder, if possible. Do not resume outdoor activities until 20 minutes has past from the last observable thunder or lightning.Organizations should adopt a Lightning Safety Policy and integrate it into their overall safety plan.TestingModern diagnostic testing is available to mimic the performance of lightning conducting devices as well as to indicate the general route of lightning through structures. This testing typically is low power, 50 watt or less. It is traceable, but will not trip MOVs, gas tube arrestors, or other transient protection devices. Knowing the behavior of an event prior to occurrence is every businessmans earnest hope. With such techniques, lightning paths can be forecast reliably.Codes & StandardsThe marketplace abounds with exaggerated claims of product perfection. Frequently referenced codes and installation standards are incomplete, out dated and promulgated by commercial interests. On the other hand IEC, IEEE, MIL-STD, FAA, NASA and similar documents are supported by background engineering, the peer-review process, and are technical in nature.SummaryIt is important that all of the above subjects be considered in a lightning safety analysis. There is no Utopia in lightning protection. Lightning may ignore every defense man can conceive. A systematic hazard mitigation approach to lightning safety is a prudent course of action.References1.API 2003, Protection Against Ignitions Arising out of Static, Lightning, and Stray Currents, American Petroleum Institute, Washington DC, December 1991. 2.Golde, G.H., Lightning, Academic Press, NY, 1977. 3.Hasse, P., Overvoltage Protection of Low Voltage Systems, Peter Peregrinus Press, London, 1992. 4.Hovath, Tibor, Computation of Lightning Protection, John Wiley, NY, 1991. 5.IEEE Std 1100, Powering and Grounding of Sensitive Electronic Equipment, IEEE, NY, NY. 1992. 6.KSC-STD-E-0012B, Standard for Bonding and Grounding, Engineering Development Directorate, John F. Kennedy Space Center, NASA, 1991. 7.Morris, M.E., et.al., Rocket-Triggered Lightning Studies for the Protection of Critical Assets, IEEE Transactions on Industry Applications, Vol. 30, No. 3, May/June 1994. 8.Sunde, E.D. Earth Conduction Effects in Transmission Systems, D. Van Nostrand Co., NY, 1949. 9.Towne, D., Wave Phenomena, Dover Publications, NY. 10.Uman, Martin, Lightning, Dover Publications, NY, 1984.中文翻译（一）防雷基础介绍闪电是一个反复无常，随机的和不可预知的事件。它的物理特性包括如下：电流有时超过400千安，温度可以高达50,000华氏度，速度接近光速的三分之一。在全球范围内，自2000年以来没秒有100次雷击发生。美国保险公司的信息显示基本上每57起赔偿就有一起是因为雷电。这些数据还不包括商业，政府和工业雷电造成的损失。雷电灾害在美国闪电每年造成超过26,000起火灾，财产损失超过5-6亿美元（新生命教育协会估计）。地球雷击现象，按照目前所知道的情况，有着如下这样一个规律1.从顶层雷云向下脉冲，寻求地面的电气目标。2.地面物体（围栏，树木，草叶，建筑物角落的人，避雷针等）在雷击时会发出不同强度的电活动度。从这些地基对象向上发送电力波动，在离地面几十米的位置，会出现一个“聚集区”加剧的电场。3.当带有异种电荷的雷云相遇时，相当于电路“开关”被关闭，于是有电流流过。这就是我们看到的闪电。闪电效果可以直接或间接的。直接的效果是电阻发热，电弧燃烧。间接影响是，电容电感的电磁影响。闪电“预防”或“保护”（在绝对意义上的）是不可能的。只能说是将其影响减小，可以通过一个整体性系统的方案来实施保护，下面就对常用的方案进行描述。避雷针从富兰克林研究雷电开始，就开始使用避雷针将雷电引流接地，保护建筑物。避雷针是现在最常用的防雷装置，根据建筑物形状，高度等因素，可以采用不同的设计避雷针来达到要求。例如，一些公用事业倾向于变电站架空屏蔽电线。在某些情况下，没有任何避雷装置的使用是适当的。高空装设避雷装置可能改变雷电的动作。在等效电子领域，钝尖杆被视为是一种有效的避雷针类型。空气终端的设计和性能，是一个有争议且未解决的问题。 “消除”闪电是一个值得怀疑的办法。进一步的研究和测试仍在进行中，为的是更加充分地了解各种高空避雷装置的作用。引下线连接 引下线应该通过一个安全的方式来安装，在已知电路外面敷设。引下线不可以涂漆，因为这样使得阻抗增加。应采用逐渐弯曲（至少8英寸半径），以避免闪络问题。建筑钢材可当做是与大地连接的引下线，但要保证所有的金属建材有效连接成网。所有金属导体都应该被连接，如燃气及水管道，信号线，空调管道，铁路轨道，桥式起重机等。金属导体之间的连接应该是焊接，而不应是机械连接。机械连接时容易受到腐蚀和物理损害。接地接地系统必须解决地球低阻抗。一个闪电的典型脉冲光谱的研究就揭示了闪电的高和低频率的内容。高频的频谱变化是非常的迅速的，达到10微秒的峰值电流。接地系统就是将雷电导入大地来减少雷电的危害。单点接地系统是将结构内的所有设备都连接到一个主母线，将这根母线连接到外部接地系统。接地系统的设计应减少交流阻抗和直流电阻。地球的零电位是接地防雷的重要原因。采用径向技术可以使阻抗降低，使雷电流发散。考虑到每一个接地导体都有一个电压梯度，可以将他们都连接到地面设施。人工降阻剂的添加是有效果的，应该在常用的方法无法降低电阻时使用，定期的检查接地电阻也是应该在计划之中。瞬变和浪涌普通熔断器和断路器不能够处理雷电引起的瞬变。防雷设备是可以使得电流分散，过滤某些频率，钳制电压水平，或执行这些任务的组合。电压钳位器紧能够处理极高的浪涌电流，以及减少极快的瞬时上升能力。采取堡垒防御是一种谨慎的行为：他可以保护主面板，保护所有相关的二次配电板，保护宝贵的插件，如过程控制仪表，计算机，打印机，火灾报警器，数据记录和SCADA系统设备设备等，此外，还能保护传入和传出的数据和信号线。保护一些远端设备，如井口，远程安全报警器，摄像机，高桅杆照明，空调等。 电涌抑制器的最小的引线长度取决于各自的电气面板。在快速上升时间时，电缆电感成为重要的高瞬态电压，可以使用较长的引线。闪电探测器，可在不同的成本和技术下，有时是可以早期预防雷电的。最为普遍的应用是，它们被用作为AC线路电源断开到雷电到来之前的备用电源。用户应当避免过度的依赖于设备，毕竟这些设备并不是每一次都是可靠的。教育所有人都应当接受防雷安全的教育，在雷雨天气。在室内或汽车时，要避免接触水和一些的金属物件;避免在制高点行车;避免在孤木下避雨;避免在雨天室外打手机。如果在附近有闪电发生，应当躲在安全的位置，丢点有的金属物件，脚蜷缩在一起，低着头，手放在耳朵上，以减少声震。保守和暂停活动，当你第一次听到雷声，如果可能的话。不要户外活动，直到20分钟过去，从远处的观察打雷或闪电。组织应采取防雷安全政策，并融入其整体安全计划。测试现代诊的仿真可以显示一般的闪电的过程。这种仿真通常是低功耗的，50瓦或更少。这是有迹可寻的，但不会跳闸MOVS，气体放电管或其他瞬态保护装置。发生之前，以了解事件的行为，是每一个商人的殷切希望。有了这样的技术，闪电路径就可以可靠的预测。规范与标准市场上有很多产品夸大其完美。经常被引用的法规和标准是不完整的，过时的但是符合和商家利益。另一方面的IEC, IEEE, MIL-STD, FAA, NASA的相关文件显示正在支持研究这一领域。总结需要注意的一点是上述的所有的雷电的防雷的措施没有一个是绝对的理想的完美的措施。 闪电的情况可能会超过每一个人的设想。雷电的系统的预防是一种有效的降低雷电灾害的方法。参考文献1. 2003年空气污染指数，对所产生的静电，火灾2008闪电和杂散电流，美国石油研究所，华盛顿特区，1991年12月。2. Golde，G.H.，闪电，学术出版社，纽约，1977。3.哈瑟，体育，低电压系统，彼得Peregrinus出版社，伦敦，1992年过电压保护。4. Hovath，蒂博尔，防雷，威利计算，纽约，1991年。5. IEEE标准1100，供电和敏感的电子设备的接地，符合IEEE，纽约州。 1992。6.肯尼迪航天中心，用于连接和接地，工程开发局，约翰肯尼迪航天中心，美国航天局，1991年标准。7.莫里斯，i，et.al.，火箭引雷研究的重要资产，在行业的应用，卷汇刊保护。 30，第3号，5 / 1994年6月。8.森德，E.D.输电系统接地传导效应，四凡诺斯特兰有限公司，纽约，1949年。9.汤，四，波动现象，多佛出版社，台北。10.乌曼，马丁，闪电，多佛出版社，纽约，1984英文资料（二）building anti-radar design standardfirst, the building anti-radar classifies the anti-radar building category which pointed out explicitly to the standard, may apply mechanically directly. in the standard to some buildings only pointed out that is bigger than estimate thunder stroke number of times xx/every year, but belongs to two kinds or three kind of anti-radar buildings. regarding these stipulations, only depends on the direct-viewing feeling and the experience in the design, cannot determine explicitly its building respective anti-radar category, causes to make two kinds anti-radar to make three kinds by mistake, should make three kinds anti-radar, but has not done, the result is to the building which completes creates certain hidden danger. this has the necessity according to the local annual mean thunderstorm day and the building locus geography, the geological soil, the meteorological environment and so on conducts the detailed research and makes the corresponding computation, determines the anti-radar rank.for example: under jinan area td=26.3 k=2 environment according to formula: n=0.024k td1.3 ae in the formula: n- building estimate thunder stroke number of times (/year)the k- correction factor (according to newly built building locuss geography, environment decides)td- annual mean thunderstorm dayae- and the building truncation receives the same thunder stroke number of times equivalent area (km2).calculates the length 100 meters, the width 25 meters, above two (h9 rice) the provincial level work building must make two kind of anti-radar. if through the computation, this kind of building actual does not make three kinds anti-radar or does not do is possible. from this sees, carries on the overall evaluation to some peculiar circumstances building and makes the corresponding computation is very essential.the two, anti-radar electric inductions and the thunder electric waves invade the against long jab thunder the measure, the general layout personnel are very explicit. but, along with the technical development, electronic installations popularization, the anti-radar electric induction and the thunder electric wave invasion must be clear in the design, and consummates gradually forms an anti-radar network. when the 1. thunder and lightning induces - the thunder discharge, has the electrostatic induction and the electromagnetic induction on the nearby conductor, it possibly causes between the metal part to produce the spark. therefore is protected in buildings metal earth, is the anti-radar electric induction key measure. first, completes the equipotential joint. to one, two kind of anti-radar buildings in parallel or overlapping placing metal pipeline, when its clear distance is smaller than 100mm, should use jin shuxian to bridge, is prevents the potential difference which the electromagnetic induction creates to be able the small gap breakdown, but produces the electric spark, every other 30m completes the earth. the 2. thunder electric wave invasion - as a result of the thunder and lightning to the air line either the metal pipelines function, the thunder electric wave possibly along these pipeline invasion room, endangers the personal safety or damages the equipment. therefore, completes the terminal the anti-radar protection, completes the equalizing ring and against flank attack thunder is the anti-radar electric wave invasion key measure. first, two kind of anti-radar construction low pressure coil in entire line uses buries straight said that is built on stilts the