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1、谐振基地系统单相接地故障选线研究 Resonatorbasesystemsingle-phasegroundingfaultlineselectionresearch 摘要本文所研究的课题主要涉及到35kV、10kV及其以下的中低压配电网,最主要的是10kV中压配电网。配电网络(DistributionNetwork)是电力系统中二次降压变电所低压侧降压后直接向用户供电的网络,一般由多条出线(架空线路或电缆线路)、降压变压器、断路器与各种开关、接地装置、通信与控制设备、测量与计量仪表及继电保护与选线装置等构成,按照一定的规则运行,以高质量的电能持续满足用户的需求。
2、在快速发展的现代社会,用电设备不断增多,不但对电能需求量越来越大,而且对供电可靠性的要求也越来越高,电网尤其是中低压配电网的容量不断扩大,其范围不断延伸,线路分支、走向复杂,电缆线路日益增多,在设计施工中质量不易保证,一方面使电网的运行可靠性降低,运行中发生接地故障的几率大大增加,另一方面电网的对地电容越来越大,一旦发生接地故障,很容易在接地点产生电弧,不但严重威胁着电力系统安全和人身安全,而且极大影响着供电可靠性,必须限制接地故障造成的危害并及时准确的排除故障。选择合适的接地方式是限制接地故障危害的有效途径,与之配合的选线或故障定位是排除故障的重要手段。运行经验表
3、明,电压等级越低,接地故障越多。从故障类型来看,最常见的是单相接地故障,约占80%以上。单相接地故障状况往往比较复杂,配电网在单相接地故障下的选线问题是接地故障处理中最具代表性的问题。关键词:谐振接地,单相接地,故障,选线 AbstractThisprojectmainlyinvolves35kV,10kVandbelowinthelowvoltagedistributionnetwork,themostimportantis10kVmediumvoltagedistributionnetwork.Distributionnetwork(Distributi
4、onNetwork)isthepowersystemoftwosubstationlowpressuresidepressuredirectlytouserpowersupplynetwork,generallyconsistingofapluralityofoutlet(overheadlineorcable),astep-downtransformer,circuitbreakerandswitch,groundingdevice,communicationandcontrolequipment,measurementandmeterandrelayprotec
5、tionandlineselectiondeviceandsoon,accordingtocertainrulesofoperation,tohighqualitypowercancontinuetomeettheneedsofusers.Intherapiddevelopmentofmodernsociety,electricalequipmentisceaselessgrowinquantity,notonlyfortheelectricitydemandisbiggerandbigger,andthepowersupplyreliabilityrequirem
6、entsarealsogettinghigherandhigher,especiallyinthelowvoltagedistributionpowernetworkcapacityexpansion,itslimitsisceaselessandoutspread,linebranch,tothecomplex,cablelineisincreasing,inthedesignofconstructionqualitycannotbeguaranteed,ononehandtheoperationreliabilityofpowergridisreduced,op
7、erationofthegroundingfaultprobabilityincreasesgreatly,ontheotherhand,capacitancetogroundofthenetworkismoreandmorebig,whengroundingfaultoccurs,easilyinthegroundingarc,notonlyseriouslythreatenthesafetyofpowersystemandsecurityoftheperson,butalsogreatlyaffectsthereliabilityofpowersupply,