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1、精品学习资源封面欢迎下载精品学习资源作者: PanHongliang仅供个人学习高 等 教 育 自 学 考 试毕 业 论 文110kv 牵引变电所防雷接地设计丁永杰专业:轨道交通供电主考学校:兰州交通高校 准考证号:指导老师姓名职称:王云松 讲师甘肃省高等训练自学考试办公室印制2021 年 4月 26 日欢迎下载精品学习资源供X电X专专业 业本科论文110kv 牵引变电所防雷接地设计欢迎下载精品学习资源110kv traction substation lightning protectionand grounding design丁永杰dingyongjie欢迎下载精品学习资源摘要变电所是电
2、力系统重要组成部分,因此,它是防雷的重要爱惜部位.雷电具有很强的危害性,因此应当重视牵引变电所雷电的防护. 假如变电所发生雷击事故,将造成大面积的停电,给社会生产和人民生活带来不便,这就要求防雷措施必需特殊牢靠.变电所是电力系统防雷的重要爱惜,假如发生雷击事故,将造成大面积的停电,严肃影响社会生产和人民生活 . 所以变电所的防雷措施必需特殊牢靠 . 变电所遭受雷击的来源及解决方案 1 雷击的来源 . 一是雷直击于变电所的设备上;二是架空线路的雷电感应过电压和直击雷过电压形成的雷电波沿线路侵入变电所. 2变电所对于直击雷的爱惜一般实行装设避雷针或接受沿变电所进线段确定距离内架设避雷线的方法解决.
3、(3) 架空线路的雷电感应过电压和直击雷过电压形成的雷电波沿线路侵入变电所,是导致变电所雷害的主要缘由,如不实行防护措施,势必造成变电所电气设备绝缘损坏, 引发事故 . 在变电所内装设避雷器的目的在于限制入侵雷电波的幅值,使电气设备的过电压不致于超过其冲击耐压值 . 而变电所的进线段上装设爱惜段的主要目的,在于限制流经避雷器的雷电流幅值及入侵雷电波的陡度. (4)变电所装设避雷针的原就全部被爱惜设备均应处于避雷针 线 的爱惜范畴之内,以免遭受雷击 .当雷击避雷针时,避雷针对地面的电位可能很高,如它们与被爱惜电气设备之间的绝缘距离不够,就有可能在避雷针遭受雷击后,使避雷针与被爱惜设备之间发生放电
4、现象,这种现象叫反击.此时避雷针仍能将雷电波的高电位加至被爱惜的电气设备上,造成事故 . 不发生反击事故的避雷针与电气设备之间的距离称为避雷针与电气设备之间防雷最小距离 . (5)雷击避雷针时,雷电流流经避雷针及其接地装置,为了防止避雷针与被爱惜设备或构架之间的空气间隙被击穿而造成反击事故,空气间隙必需大于最小安全净距 . 为了防止避雷针接地装置与被爱惜设备或构架之间在土壤中的间隙被击穿而造成反击事故,空气间隙必需大于最小安全净距 . (6)对于 35kV 及以下的变电所,因其绝缘水平较低, 必需装设独立的避雷针,并中意不发生反击的要求.对于 110kV 以上的变电所,由于此类电压等级配电装置
5、的绝缘水平较高,可以将避雷针直接装设在配电装置的构架上,因而雷击避雷针所产生的高电位不会造成电气 设备的反击事故 . 装设避雷针的配电构架,应装设帮忙接地装置,该接地装置与变电所接地网的连接点,距主变压器的接地装置与变电所的接地网的连接点的电气距离不应 小于 15m.其作用是使雷击避雷器时,在避雷器接地装置上产生的高电位,沿接地网向变压器接地点传播的过程中逐步衰减,使侵入的雷电波在达到变压器接地点时,不会 造成变压器的反击事故 . 由于变压器的绝缘较弱,同时变压器又是变电所的重要设备, 故不应在变压器的门型构架上装设避雷针.由于变电所的配电装置至变电所出线的第欢迎下载精品学习资源一杆塔之间的距
6、离可能比较大,如答应将杆塔上的避雷线引至变电所的构架上,这段导线将受到爱惜,比用避雷针爱惜经济 . 由于避雷线两端的分流作用,当雷击时,要比避雷针引起的电位上升小一些 . 因此, 110kV 及以上的配电装置,可将线路避雷线引接至出线门型构架上,但土壤电阻率大于1000 m的地区,应装设集中接地装置. 对于 3560kV 配电装置,土壤电阻率不大于500m 的地区,答应将线路的避雷线引接至出线门型 构架上,但应装设集中接地装置 . 当土壤电阻率大于 500m 时,避雷线应终止于线路终端杆塔,进变电所一档线路爱惜可用避雷针爱惜. 牵引变压器的设计主要包括变压器的容量运算和技术指标的检测,设计必需
7、符合高(低)压侧主接线的设计要求. 绝缘设备的检验主要是关于电气设备的动稳固、热稳固性、开关设备的选型和校验,以及对室内外母线,各个支持绝缘子和穿墙套管,电压、电流互感器的选型和校验. 另一部分主要内容是对牵引变电所的防雷接地设计,包括避雷针、避雷线、避雷器以及接地系统的设计 . 牵引变压器的设计主要包括变压器的容量运算和技术指标的检测,设计必需符合高(低)压侧主接线的设计要求. 绝缘设备的检验主要是关于电气设备的动稳固、热稳固性、开关设备的选型和校验,以及对室内外母线,各个支持绝缘子和穿墙 套管,电压、电流互感器的选型和校验. 另一部分主要内容是对牵引变电所的防雷接地设计,包括避雷针、避雷线
8、、避雷器以及接地系统的设计.本文表达了雷电、雷电压和雷电流的形成过程,并给出了雷电参数,阐述了防雷装置如避雷针、避雷器的防雷原理以及爱惜范畴,给出了直击雷和感应雷的防护方 案,介绍了目前我国牵引变电所防雷接地设计中常用的几种措施,如:合理选择牵引变电所修建的地理位置,架设避雷针、敷设接地网,在进线段装设避雷器,同时对几种防雷措施进行了深化的论述和定量的运算分析. 基于常用的防雷接地的设计方法,对110kv 牵引变电所进行了详细的防雷接地设计 . 设计中,结合当地现状,综合考虑了气候、地势、环境等多种因素,给出了较好的防雷接地爱惜方案. 通过对牵引变电所的防雷接地设计,全面剖析了电力系统中如何让
9、提高牵引变电所的防雷水平,从而有效地降低牵引变电所的雷击事故,削减雷电对电网安全运行的影响.关键词:牵引变电所;防雷接地;雷电放电;雷电流论文类型:应用争辩AbstractThe lightning has very strong harmfulnesss we should pay attention to drawing the shelter of the lightning of transformer substation.Substation power system is important to the mine facilities, iflightning accident
10、occurred, causing widespread power outages, and seriously affect the sociparloduction and people s life .Therefore asked the substation lightning protection measures must be very reliable.欢迎下载精品学习资源Substation lightning source and solution method. 1 Lighting source. Direct lightning stroketo substati
11、on equipmen;ttwo is the overhead line lightning induced overvoltage andlightning over.voltage lightning wave intrusion formed along the line of substation.2substation lightning protection for generally taken with a lightning rod or a substation incoming line within a certain distance of the lightnin
12、g line method to solve erection.3the overhead line lightning induced overvoltage and lightning over.voltage lightning wave intrusion formed along the transmission line substation, is the leading cause of substation lightningis the main reason,if do not take protective measures, is bound to cause the
13、 substation electrical equipment insulation damage, cause an accident, Intransformer substation arrester installed aims to limit intrusion of lightning wave amplitude, so that the electrical equipment of the over voltage not to exceed its impulse withstand voltage value.While the substation incoming
14、 lines installed protection section of the main purpose is to restrict the flow through the surge arrester, lightning current amplitude and intrusion of lightning wave steepness. 4 Substation with a lightning rod principle all the protected equipment shall be kept in a lightning rod wire within the
15、scope of protection, to avoid being struck by lightning. When the lightning arrester, lightning rod on ground potentials can be very high, as they and the protected electrical equipment struck by lightning, the lightning rod and protected equipment occurred between the dischargpehenomenon,sthispheno
16、menon is called back. The lightning arrester can still be lightning wave highpotentials to the protected electrical apparatus, causing the accident. No impact accidents lightning minimum distance between the electrical equipment.5lightning arrester, lightningcurrent flowing through the lightning con
17、ductor and earthlingdevicein orderto prevent the lightning rod and theequipment being protected or framework of the air gap between the breakdown was caused by impact accident, air gap must be greater than the minimum distance of An Quanjing.Inorder to prevent lightning grounding device and theequip
18、ment being protected or between frames in soil of the gap breakdown caused by impact accident, air gap must be greater than the minimum distance of An Quanjing.6for 35kv and below the power substation, because of its low insulation level, must be arranged independently of the lightning rod, and meet
19、 the requirements not counterattack.For more than 110kv substation, such as voltage grade power distribution device insulation level is higher, can be directly installed on the distribution of lightning rod device structure, and lightning arrester of the resulting high potential does not cause elect
20、rical equipment against accidents. Witha lightningrod for distributionframe, should installauxiliary grounding device, the grounding device of substation grounding grid connection point, away from the main transformer grounding device of substation grounding grid connection point electric distance s
21、hall not be less than 15m. Its role is to enable the lightning arrester, the arrester grounding device has high potential, along the grounding transformer ground to spread gradually in the process of decay, which penetrated the lightning in the transformergrounding, does not cause transformer strike
22、 accident. Due to the insulation of the transformer欢迎下载精品学习资源is weaker, at the same time the transformer is the important equipment of substation, it should not be in the transformer type door frame is provided with a lightning arrester. As a result of substation power distribution device to substat
23、ion outlet of the first tower distance may be relatively large, such as allowing the tower lightning conductor of the lead to the substation framework; the conductor will be protected, than withlightning protection economy. The lightning lines at both ends of the shunt effect, when lightning strikes
24、, than lightning induced potential rise of some small. Therefore, 110kV and above power distribution device, lightning arrester line can be guided and connected to the outlet door type frame, but the soil resistivity greater than 1000 ohm m area, should be installed with a centralized grounding devi
25、ce. In 35 60kV soil resistivity distribution device, not more than 500 ohms m area, allowing the linelightning wire guided and connected to the outlet door type frame, but should be installed with a centralized grounding device. When the soil resistivity greater than 500 ohm m, lightning conductors
26、shall be terminated in line terminal tower, into a line of substation protection available for lightning rod protection. Traction transformer design mainly includes the transformer capacity calculation and testing indicators the design must accord with high lowpressure side main wiringdesign require
27、ments. Insulation equipment inspection is mainly about electrical equipment dynamic stability, thermal stability, switching equipment selection and validation, as well as indoor and outdoor bus, each support insulator and bushing current transformer, voltage, the selection and validation. Another pa
28、rt isthe main content ofthe traction substation lightningprotection and grounding design, including lightning,lightning,lightningarrester and the design ofgrounding system. Traction transformer design mainlyincludesthe transformercapacitycalculationandtesting indicators ; the design must accord with
29、high low pressure side main wiringdesign requirements. Insulation equipment inspection is mainly about electrical equipment dynamic stability, thermal stability, switching equipment selection and validation, as well as indoor and outdoor bus, each support insulator and bushing current transformer, v
30、oltage, the selection and validation .Another part is the main content of the traction substation lightning protection and grounding design, including lightning, lightning, lightning arrester and the design of grounding system. The traction transformer design includes transformer capacity computing
31、and technology indicators testing, design must meet the high low pressure side of the main connection of the design requirements. Insulation test equipment for electrical equipment mainly on the dynamic stability, thermal stability, switching equipment selection and validation, as wellas indoor and
32、outdoor bus, each supporting insulators and wall bushings, voltage, current transformer selection and check. Another part of the main content is the design of substation grounding lightning protection, including lightning, grounding wire, surge arresters and grounding system design.This text describ
33、es the lightning, thunder and lightning current voltage forming process, and gives the lightning parameter, elaborated the lightning protection device, such as a欢迎下载精品学习资源lightning rod arrester lightning protection principle and the scope of protection, gives thethunder and lightning induction prote
34、ction scheme, introduced at present our country traction substation lightning protection and grounding design commonly used in several measures, such as: rational selection of traction substation building location, set lightning rod, laying grounding grid, into the line arrester installed, at the sa
35、me time to several protection measures were discussed and the quantitative calculation and analysis. Based on the commonly used in lightning protection and grounding design method, the 110kV traction substation arediscussed in detail the design of lightning protection grounding. In the design, combi
36、ned with the local situation, considering terrain, climate, environment and other factors, has given the good grounding for lightning protection scheme. Based on the traction substation lightning protection and grounding design, comprehensive analysis of power system how to improve traction substati
37、on lightning protection level, thereby effectively reducing traction substation lightning accident, reduce lightning influence on safe operation of power grid.Key words: traction substation; lightningprotection; lightning currentType of thesis: Application Research欢迎下载精品学习资源目录摘要 I引言错误!未定义书签;一 雷错误!未定
38、义书签;1 雷电错误!未定义书签;1.1 雷电的形成 错误!未定义书签;1.2 雷电的放电 221.3 雷电放电过程 181.3.1 先导过程 181.3.2 主放电过程 31.4 雷电的危害 31.5 雷电的防护 32 雷电参数及防雷装置 42.1 雷电参数 72.1.1 雷击时的等值电路 62.1.2 雷电流 72.1.3 雷暴日与雷暴小时 92.1.4 地面落雷密度 17 3 防雷设备 103.1 爱惜原理 103.2 爱惜范畴 12二避雷器 151 避雷器的分类及比较 162 阀式避雷器电气特性的基本参数 193 金属氧化物避雷器电气特性参数194 避雷针和避雷线 错误!未定义书签;5
39、. 防雷接地的概述 错误!未定义书签;5.1 防雷接地的进展简况 错误!未定义书签;5.2 接地与防雷接地 错误!未定义书签;三 冲击电流流经接地装置入地时的基本现象281 土壤中的电位分布 282 土壤中的电场强度 233 接地装置的电感效应及利用率 234 防雷接地装置的形成及其电阻的算法24欢迎下载精品学习资源5.牵引变电所防雷接地的必要性 26四 110KV 牵引变电所防雷爱惜和接地设计1 直击雷爱惜 28282 雷电侵入波爱惜 282.1 爱惜措施 282.2 避雷器的设置 292. 3 变电站的爱惜 293 110kv 高压输电线路的防雷爱惜 303.1 雷电对输电线路的危害 30
40、3.2 线路雷击跳闸的两种主要表现形式303.3 线路雷击跳闸分析 303.4 有避雷线的线路雷击跳闸率的确定323.5 有避雷线线路的雷击跳闸率 324 牵引变电所进线段的爱惜 335. 牵引变电所内变压器的防雷接地爱惜365.1 双绕组变压器的防雷爱惜365.2 三绕组变压器的防雷爱惜365.3 自藕变压器的防雷爱惜 375.4 变压器中性点的防雷爱惜 38结论 40致谢 41参考文献 42附录 43附录 2.2110kv 变电站用氧化锌避雷器电气特性43引言电力工业是国民经济的一项基础工业和国民经济进展的先行工业,它是一种将煤、石油、自然气、水能、核能、风能等一次能源转换成电能这个二次能
41、源的工业, 它为国民经济的其他各部门快速、稳固进展供应足够的动力,其进展水平是反映国家经济进展水平的重要标志 .变电站是联系发电厂和用户的中间环节,起着变换和支配电能的作用. 这就要求变电所的一次部分经济合理,二次部分安全牢靠,只有这样变电所才能正常的运行工作,为国民经济服务 .欢迎下载精品学习资源雷电 Lightning 是一种大气自然现象,对人类社会而言,雷电有时也会造成自然灾难 . 随着社会的进展,雷电给社造成的危害越来越严肃,同时雷电防护 Lightning Protection 科学技术也在人类熟识自然、抵抗自然灾难的过程中不断进展.全球任何时刻大约有2000 个地点遏上雷暴,平均每
42、天约发生800 万次闪电,每次闪电在微秒级的瞬时释放出约55kW.h 的能量 . 我们生存的环境既被动地接受自然灾难的侵袭,又能动地为灾难的形成和进展供应条件. 从久远的过去开头,雷电就对人类、人类赖以生存的自然资源和人类制造的物质文明构成巨大的威逼,例如,森林火灾有 50以上因雷电引发;人们居住生活的建筑物屡遭雷击破坏;电力、石化等工业设施常因雷击而发生灾难性事故. 不难看出,雷电灾难的范畴随社会经济进展而扩大,其表现形式随其范畴扩大而复杂 .相伴电力系统中所用电气元件产品诸如断路器、继电器、隔离开关等性能指标的提高,变电站的功能也会越来越完善,牢靠性也会得到很大的提高. 因此,提高变电所防
43、雷爱惜科技水平势在必行 .一、雷1、雷电1.1 雷电的形成雷电放电是带电荷的雷云引起的放电现象,在某种大气和大地条件下,潮湿的热气流进入大气层冷凝而形成雷云,大气层中的雷云底部大多数带负电,它在地面上感应出大量的正电荷,这样,雷云和大地之间就形成了强大的电场,随着雷云的进展和运动,当空间电场强度超过大气游离放电的临界电场强度时,就会发生雷云之间或雷云对地的放电,形成雷电 . 按其进展方向可分为下行雷和上行雷 . 下行雷是在雷云产生并向大地进展的,上行雷是接地物体顶部激发起,并向雷云方向发起的 .主放电时电流可达数千安,最大可达 200 300kA. 余辉,雷云中剩下的电荷连续沿主放电通道下移,
44、称为余辉放电阶段 .余辉放电电流仅数百安,但连续的时间可达 0.03 0.15 s.1.2 雷电放电雷电放电是由带电荷的雷云引起的放电现象. 一般认为雷云是在某种大气和大地条件下,由强大的潮湿的热气流不断上升进入淡薄的大气层冷凝的结果. 猛烈的上升气流穿过云层,水滴被撞分裂带电 . 略微的水沫带负电,被风吹得较高,形成大块的带负电的雷云;大滴水珠带正电,凝聚成雨下降,或悬浮在云中,形成一些带正电的区域. 雷云的底部大多数是带负电,它在地面上会感应出大量的正电荷. 这样,在带有大量不同极性或不同数量电荷的雷云之间,或者雷云和大地之间就形成了强大的电场,其电位差可达几兆伏甚至几十兆伏 . 随着雷云
45、的进展和运动,一旦空间电场强度超过大气游离放电的临界电场强度时,就会发生雷云之间或雷云对地的放电. 大多数雷电放电发生在雷云之间,对地面上的设备和建筑没有什么直接影响. 雷云对地的放欢迎下载精品学习资源电虽占少数,但危害是特殊严肃的,是造成雷电事故的主要因素. 要防止产生雷电事故,就必需对雷电的放电过程、活动规律和雷电参数加以争辩.1.3 雷电放电过程按雷电进展的方向可区分为下行雷和上行雷两种. 下行雷是在雷云产生并向大地进展的,上行雷是由接地物体顶部激发起,并向雷云方向进展的. 雷电的极性是依据从雷云流人大地的电荷的符号准备的 . 实测说明,不论地质情形如何, 90左右是负极性雷. 正极性雷
46、和上行雷显现的机会较少,下面介绍最常见的下行负极性雷放电的特性.1.3.1 、先导过程雷云对大地的放电通常包括如干重复的放电过程,每次放电都由先导放电和主放电组成 . 图 6 1a 是由高速旋转的照相机摄下的负雷云对地放电的典型照片.如图 6la所示,第一次从雷云向大地进展的先导有逐级跳动进展的性质, 叫梯级先导 . 每一级的长度为 10 一 200m,平均 50m,梯级间的间歇时间为 10 100s,平均 50s,第一先导的传播速度为 1 8XlO5m s,即约为光速的 l 1000 左右. 先导通道具有良好的导电性,因此带有与雷云同极性的负电荷. 雷云与先导的电荷在大地上感应出异号的正电荷
47、,当电荷积存到确定程度时仍会显现自下向上发展的逆先导 .1.3 2 主放电过程当先导进展到接近地面时,就在通道端部显现高场强,使空气猛烈游离而产生 高密度的等离子区 . 此区域沿先导通道自下而上快速传播,形成一条高电导率的等离 子体通道 . 使先导通道以及雷云中的电荷与大地的电荷相中和 需要留意的是,这里所说的“中和”并不愿定指正、负离子复合,只要在每个很小的空间内,异号离子的浓度相同,就可以说是中和了 . 这个过程就是主放电过程 . 主放电进展的速度比先导进展速度快得多,达到 15X107 一 15X108m s1 20 1 2 的光速 .1.4 雷电的危害雷电是自然界存在的物理现象,打雷是指带正负电荷的雷云之间或是带电荷的雷 云对大地快速放电而产生的声和光 .雷云之间正负电荷放电现象,就是我们平常看到天空闪光和随之而来的巨大隆隆声 .天空打雷对现代微电子的电气设备有损害,但对自然界生物和净化空气特殊有好处 .但是天空中带电