简介:已有许多资料证明陡波前冲击电压的存在,并在公用事业和石化工业范围里得到了公认。涉及这一课题的技术文献将设计人员和用户的注意力对准许多大型交流电动机因陡波前操过电压引起的故障,例如由空气断路器、真空断路器和站用断路器产生的过电压。由于这种过电压在绕组上非均匀分布,所以在定子绝缘内会产生危险应力。此外,还要指出的是:目前还缺乏应用于静止设备那样的令人满意的国家标准可用来规定旋转电机应有的承受冲击电压的能力,致使许多大型交流电动机存在不协调性、不确定性,从而引起故障。本文根据现有的技术文献,最近的国内研究工作和用户经验,提出了规定匝间绝缘承受过电压额外介电强度以及制订验收的国家标准和试验要求的必要性。本文不打算讨论避雷器的应用问题,因为已有许多IEEE论文对此课题进行了多方面的广泛报道。
简介:Beingabundantinhydropower,coal,windenergyandsolarenergyetc.,NorthwestChinaisanimportantenergybasewithgreatpotential.Inrecentyears,alongwiththevigorousdevelopmentoftheenergybase,the
简介:±500KVHVDCTransmissionprojectfromTianshengqiaotoGuangzhouLiLicheng,PengBaoshu,YuJianguo,WuZehuiPowerNetwork,ConstructionDepar...
简介:Theretrofitprojectof800-kVlargecapacityexperimentsysteminXi'anHighVoltageEquipmentResearchInstitutewascompletedsometimeago.Thesystemcanmeetrequirementsofwholepoleexperimentof550-kV63-kAand800-kV63-kAcircuitbreakersbyIECNorm.Itscapacitortowerisover100tinweightand15minheight.Thevoltageofeachcapacitorbankcanreach1000kV.
简介:OnJanuary10,2011,the750-kVTurpan-Bayinguolengtransmission-substationprojectofXinjiangpowergrid,officiallywentintooperation.Henceforth,thehardtimeofstaggeringpowerutilizationandlimitingpowerutilizationinpeakperiodinBazhou,Aksu,Kashi,KezhouandHotanfiveprefecturesinsouthXingjiangwillneverreturn.
简介:Helicopterinspectionofultrahighvoltage(UHV)transmissionlineshasunmatchedadvantagescomparedtomanualworkduetotheinspectionangleandhigh-techequipmentonboard,especiallyindetailedinspectionsoftowerheadsanddefect-detectionsinvirtueofinfrared/ultraviolettechniques.Thispaperdealswithsomekeytechnicalproblemsintheinspectionsof1000kVUHVAClineswithahelicopter,suchasthesafedistanceoflive-lineworking,electromagneticfieldintensityandflightcontrol.Basedonthestudyresults,asetofUHVlineinspectionmethodswasworkedoutandappliedtotheinspectionofliveUHVlines.
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简介:AccordingtothepowersystemplanninginChina,500kVtransmissionlinewillbethetrunksinallregionalnetworksexcepttheNorthwestChinaSystem.Duetoshortofcapitalresources,however,mostofthose500kVtransmissionlinesareandwillbeoperatinginsinglecircuitforquitealongpe-riodoftime.So,tousetheliveworkingtechniqueson500kVlinesisanimportantproblemforstudy.Actually,wehadalreadybegunourstudyonliveworkingon500kVtransmissionlineseveralyearspriortothePing-Wu
简介:局部放电是额定6kV或变高电压的电动机与发电机中发现的大多数定子绕组绝缘劣化机理的表征,因而,对局部放电的测试作为确定这类高压电机定子是否需要维修的一种方法已应用了40多年,由于这种测试的好处越来越为人们所认识,也就有了将局部放电测试应用于4kV电动机与发电机绕组的兴趣,本文论述了可能限制4kV定子测试的理论上的原因,陈述了一系列表明局部放电确实发生的脱线局部放电试验的结果,过去两年中对大约10台4kV电动机上进行的一系列在线局部放电试验的结果表明局部放电只可能发生在由于一些类型的故障机理引起的故障发生之前很短一段时间,因此,为了防止在使用中出现故障,有必要进行连续监测,本文对一种便宜的连续局部放电监控器进行了描述,局部放电监测似乎在只用于非常关键生产过程的电动机及发电机上,才是有成本效益的,因为运行中的可能引起巨大的经济损失。
简介:Thestrengthofthepowerfrequencyelectricintensityandmagneticfieldofthe500-kVdoublecircuittransmissionlineswascalculatedbyusingtheequivalentchargemethodandtheAmpere'sLaw,andtheenvironmentalimpactfactorsofthefieldswereevaluated.Byoptimizingthephasesequence,thefrequencyelectricintensityandmagneticfieldstrengthcanbereduced.Withinadistanceof25mfromthecenterofthetransmissionline,thepowerfrequencyelectricintensityandmagneticfieldstrengthfalloffsharplywiththedistanceincrease.Finally,thebestphasesequenceandtheminimumgroundclearanceofthetransmissionlineswereobtainedtomeettherequirementsoftheleastimpactonenvionment.
简介:OnDecember28,2000,330kVShenmuSubstation,akeyoneof330kVYulin-Shenmupowertransmissionandsubstationprojects,hasbeensuccessfullyputintooperation.Itmarkedthatthewhole330kVtransmissionandsubstationprojectofShaanxi’sextra-highvoltagegridhadbeencompleted.Allthe330k