- 1、本文档共40页,可阅读全部内容。
- 2、有哪些信誉好的足球投注网站(book118)网站文档一经付费(服务费),不意味着购买了该文档的版权,仅供个人/单位学习、研究之用,不得用于商业用途,未经授权,严禁复制、发行、汇编、翻译或者网络传播等,侵权必究。
- 3、本站所有内容均由合作方或网友上传,本站不对文档的完整性、权威性及其观点立场正确性做任何保证或承诺!文档内容仅供研究参考,付费前请自行鉴别。如您付费,意味着您自己接受本站规则且自行承担风险,本站不退款、不进行额外附加服务;查看《如何避免下载的几个坑》。如果您已付费下载过本站文档,您可以点击 这里二次下载。
- 4、如文档侵犯商业秘密、侵犯著作权、侵犯人身权等,请点击“版权申诉”(推荐),也可以打举报电话:400-050-0827(电话支持时间:9:00-18:30)。
查看更多
常见的电力专业英语14-电力系统中的高电压技术
Lighting Conductors Lighting Conductors Lightning Shielding of Transmission Lines When lightning makes a direct hit on a transmission line, it deposits a large electric charge, producing an enormous overvoltage between the line and the ground. The dielectric strength of air is immediately exceeded and a flashover occurs. Lightning Shielding of Transmission Lines The arc between the line and the ground produces a highly ionized path which behaves like a a conducting short-circuit. Consequently, the normal AC line voltage immediately delivers a large AC current that follows the ionized path. This follow-through current may sustain the arc until the circuit breakers open at the end of line. Lightning Shielding of Transmission Lines Direct hits on a transmission line are rare. More often, lightning will strike the overhead ground wire that shields the line. In the latter case, a local charge shill accumulates on the line, producing a very high local overvoltage. Overhead Ground Wires Overhead Ground Wires Lightning Arresters Travelling Waves The concentrated charge immediately divides into two waves that swiftly move in opposite directions at close to the speed of light. The height of the impulse wave represents the magnitude of the surge voltage that exists from point to point between the line and the ground. The peak voltage may attain one or two million volts. * 电力系统中的高电压技术 电气工程学院 High-Voltage Technology In Power Systems Topics Insulation Grounding Overvoltage Lightning Shielding Insulation 1 Insulation is required to keep electrical conductors separated from each other and from other nearby objects. The choice of material is dictated by the requirements of the particular application and by cost. Insulation 2 The coils of generators and motors may be insulated with various tapes. The insulation on power transformer windings is commonly paper tape and pressboard operated under oil. Insulation 3 Overhead lines are supported on porcelain insulators. Between the
您可能关注的文档
最近下载
- 中、高级车险核赔职称考试试题.docx
- 暗网风险解读与防范.pptx VIP
- 数学新课程标准解读课件市公开课金奖市赛课一等奖课件.pptx
- 《多边形的面积》单元整体教学说课课件(共31张课件)--人教版五年级上册数学.ppt.pptx VIP
- 《战略品牌管理》.ppt
- (必威体育精装版)24年秋统编一年级语文上册语文园地一【精品课件】.pptx
- 新人教版七年级上册生物全册教案(2024年秋季新版教材).docx
- 新苏教版一年级上册数学全册教学课件(2024年新教材).pptx
- 部编版一年级音节拼读+生字练习全汇总.pdf
- T-D-T 1036-2013 土地复垦质量控制标准(正式版).docx VIP
文档评论(0)