发电厂接地系统设计规定 中英文.docx

发电厂接地系统设计规定一、GrO八dingSgSteMDeSig八接地系统设计ThegroundingandlightningprotectionsystemshallbedesignedperIEEE-80andlocalcodesandstatutes,andshallconsistofanintegratednetworkofgroundingconductorsandgroundrods.ThefinalnumberofgroundingrodsandtheactualquantityofgroundingconductorsshallbebasedupontheJobSitetopography,ananalysisofexistingsoildata,andtheContractor'ssoilresistivitytesting.Allgroundingconductorsutilizedinthegroundingsystemshallbebarezhard-drawncopperthroughout.Allgroundingrodsshallbethree(3)metersminimumlength,copper-weld-typethroughout.Allgroundingtestwellsshallbepre-castconcretethroughoutwithdistinctiveflushsurface-mountedremovablecovers.接地与防雷保护系统应根据电气与电子工程师协会-80及地方规范和法规行设计，并且应由接地导线和接地棒组成的综合接地网。接地棒的最终数量和接地导线的实际数量应根据工程现场地势条件，现有土壤数据分析，以及承包商土壤电阻率测试结果最终确定。接地系统中使用的所有接地导线应采用硬铜裸导线。所有接地棒的长度至少为三(3)米，并且应采用铜焊接地棒。所有接地测试并应采用预铸混凝土，并且配有找平安装可移除井盖。Thegroundingsystemshallbedesignedtoachievethefollowing:接地系统的设计应能够满足以下条件：1. Establishaminimumresistancetoearthatalllocationsnottoexceedone(1)ohm.各位置最小接地电阻不得超过一（1）欧姆。2. Protectpersonnelfromdangerouspotentialssuchastransferred,stepandtouchpotentialsduringbothnormaloperatingandmaximumgroundfaults.保护人员免受危险影响，例如在正常操作或最大接地故障情况下发生传递电位、跨步电压或接触电压。3. Provideconnectiontogroundforpowerequipmentneutrals.为电力设备中性点提供接地。4. Facilitaterelayinginclearinggroundfaults.促进接地故障保护继电器清除接地故障。5. Safelyandeffectivelydissipatelightningcharges.安全有效地使雷电电荷消散。AllFacilityelectricalequipment,includingboththeabove-gradeandbelow-graderacewaysystems,allmotorframes,andallswitchyardapparatusshallbetiedtothegroundingsystemandtoeachother.AllFacilitymechanicalapparatus,includingalloutdoorandbuildingsteelsupportcolumns,platforms,stairways,elevatedstructures,andmetallictanksandvessels,shallbetiedtothegroundingsystem.所有设施电气设备，包括地上与地下电缆管道系统.所有电机座和所有开关站装置，应与接地系统及彼此连接。所有设施机械设备，包括所有室外和建筑钢制支撑柱.平台.楼梯、高架结构.金属罐和容器应与接地系统连接。InboththeGISbuildingandtheoutdoorFacilityswitchyardareas,thegroundingsystemshallbeasubsurfacerectangulargroundinggridcomposedofoverlapping240mm2minimumcopperconductor,arrayedona4.57meterx4.57metermaximumconductorspacing.Thisrectangulargroundinggridshallextendunderalltransformerbasinsfoundationszunderthefoundationsofallhighvoltagedisconnectswitches,undertheGISswitchgearbuildingfoundations,underallswitchyardequipmentsupportstructures,andjustbeyondtheperimeterfencingoftheswitchyard.Thediametrically-oppositecornersofallpowertransformerandlightningprotectionequipmentshallbeconnectedtothegroundinggridvia240mm2minimumcopperconductor.Allotherswitchyardelectricalequipment,andassociatedsteelcolumns,steelsupports,platforms,andmetallicstructureswithintheswitchyardshallbetiedtothegroundinggridvia120mm2minimumcopperconductor.在GIS建筑和室外设施开关站区域，接地系统应采用地下矩形接地网，该接地网由排列于最大4.57米X4.57米的导线间距上的最小截面240平方毫米的铜导线组成。该矩形接地网应延伸至所有变压器地坑/地基、所有高压隔离开关基础、GIS开关设备建筑物地基、所有开关站设备支架结构的下方，以及开关站周围围栏上方。所有电力变压器和防雷设备对角应通过横截面至少为240平方毫米的铜导线与接地网连接。所有其他开关站电气设备和开关站内相关钢柱、钢支架.平台和金属结构应通过横截面至少为120平方毫米的铜导线与接地网连接。InallotherFacilityareas,thegroundingsystemshallconsistofsubsurface120mm2minimumcopperconductorinamainloopconfigurationwithmultiplelaterals.ThisgroundingloopshallextendaroundalloftheequipmentprovidedwithintheFacility;withatleasttwo(2)120mm2tie-backgroundconnectionsbetweentheFacilityandtheswitchyardarea.在所有其他设施区域，接地系统应由位于主回路配置中，带多个支线的地下横截面至少为120平方毫米铜导线组成。接地回路应在设施内提供的所有设备周围延伸，并且至少在设施与开关站配电设备区域间设置两(2)根横截面至少为120平方毫米的回接型接地线。GroundingconnectionsmadetoallFacilityelectricalswitchgearandpowerapparatusratedabove11kVshallutilize120mm2minimumriserconductor.GroundingconnectionsmadetoallFacilityelectricalswitchgearandpowerapparatusratedabove6kVzincludingallstructuralsteelcolumnsandmotorsratedabove2000kWzshallutilize120mm2minimumriserconductor.All480V-ratedSwitchgearzswitchboards,MCCszandallmotorsratedabove185kW;alongwithallcabletrayszmajorplatforms,andlargemetallicstructures,tanksandvessels;shallutilize70mm2minimumrisercopperconductor.TheminimumgroundrisercopperconductorsizeforgroundingconnectionsmadetoFacilityelectricalequipmentrated240VandbeIowzallmotorsratedupto185kW,alongwithmiscellaneoussteelsupports,stairways,fences,andsmallmetallicstructuresshallbe35mm2.设施额定电压在11千伏以上的所有电气开关设备和电力设备的接地连接应使用横截面至少为120平方毫米的立式导线。设施额定电压在6千伏以上的所有电气开关设备和电力设备，包括所有结构钢柱和额定功率在2000千瓦以上的电机，其接地连接应使用横截面至少为120平方毫米的立式导线。所有额定电压为480伏的开关设备、配电盘、马达控制中心以及所有额定电压在185千瓦以上的电机；和所有电缆桥架.主要平台和大型金属结构.罐体和容器应使用横截面至少为70平方毫米的立式铜导线。设施额定电压在240伏及以下的电气设备，额定功率在185千瓦以下的电机，以及其他钢支架、楼梯、围栏和小型金属结构应使用横截面至少为35平方毫米的接地立式铜导线。Allgroundinggridcrossingsandallgroundinglooplateralsshallbemechanically-bondedorthermally-welded.Jointsinthegroundgrid,allriserconductorconnectionstoequipmentandstructures,andallundergroundlateralconnectionsshallbe"BurndyHygroundIrreversible"compression-typecross,teezandsingle-holelugconnectors,orshallbeweldedbyuseof''Cadweld"insuchamannerthattheresistanceoftheconnectionshallbelessthanthatoftheequivalentlengthofconductor.所有接地网交叉点和所有接地回路支线应采用机械结合或热焊接。接地网中的接头、所有立式导线与设备和结构物的连接件，以及所有地下横向连接件应采用“BurndyHygroundIrreversible"压接式十字型.T型和单孔凸耳式连接器，或使用放热焊接，并确保连接电阻小于等长导线电阻。Asaminimum,thelightningprotectionsystemshallconsistofairterminals,overheadgroundingwires,surgearrestors,concentrationgroundingpolesandrelatedconnectingdownwires.TheFacilitystructuresthatwillrequirelightningprotectionsystemshallbedeterminedduringthedetaileddesignstage.最低要求，防雷系统应由接闪器接闪线.电涌保护器、集中接地极和有关的引下线组成。需要使用防雷保护系统的设施结构应在详细设计阶段确定。二、CrobmdkgSgSteMlata(latio接地系统安装Nolessthantwenty(20)groundrodsshallbefurnishedandconnectedtothegroundingsystemutilizing120mm2minimumriserconductortoachieveuniformminimumgroundresistanceacrosstheentireFacility.ThesegroundrodsshallbeinstalledthroughouttheFacilityareatominimizevoltagegradientswhichmayoccurduringfaults.Atleastsix(6)ofthesegroundingrodsshallbeprovidedwithingroundtestwellszsituatedindifferentareasoftheFacilityinreadily-accessiblewidely-dispersedlocations,withgroundrodconnectionmadeviaboltedlugarrangementtofacilitatefutureexpansionandperiodictesting.应提供至少二十（20）根接地棒，并将上述接地棒通过横截面至少为120平方毫米的引上导线与接地系统连接，以确保整个设施实现最小统一接地电阻。上述接地棒应安装于设施区域内各个位置，以尽量降低故障期间可能发生的电压梯度。其中，至少应有六（6）根接地棒应安装在接地测试井内，位于设施不同区域内广泛分散且便于到达的位置，且通过螺栓接头实现接地棒连接，从而便于将来发展和定期测试。Groundconductorrisersshallberunundergroundfromthegroundinggridtoeachbuildingcolumnandtoeachindoorequipmentsupportskidandeachoutdoorequipmentassemblyframe.Thesegroundconductorrisersshallbe120mm2minimumthroughout.接地引上导线应从地下接地网连接至每根建造型钢柱.每个室内设备支架滑轨和每个室外设备装配架。上述接地导线竖管的横截面应至少为120平方毫米。Buriedgroundingconductorsextendingbeyondfoundationsshallhaveatleast0.45metersofgroundcover.Afterinstallation,thetrenchshallbebackfilledandfirmlycompactedtomaintainstructuralintegrityofthecompactedfillmaterials.延伸至基础外围的埋设接地导线埋深至少为地下0.45米。安装完毕后，沟渠应回填，并夯实以保持夯实填土材料的结构完整性。ToensureastationgroundfaultreturnpathoflowimpedanceandtointerconnectremotegroundingrodstothemainFacilitygroundinggrid,two(2)120mm2minimumgroundconductorsshallbeburiedwithallelectricalductbanksandelectricaltrenches.Alongtheductbankandelectricaltrenchroutings,thesegroundconductorsshallbeconnectedtothemainFacilitygroundinggridsystem,theswitchyardgroundinggrid,outlyingbuildinggroundinggridstraversed,andallassociatedmanholegroundingsystems.为了确保低阻抗接地故障返回路径，并将远程接地棒与主设施接地网连接，应将两(2)根横截面至少为120平方毫米的接地导线与电气管道组和电缆沟一并埋设。沿着管道组和电缆沟的路径，上述接地导线应与主设施接地网系统.开关站接地网.外围建筑接地网以及所有相关检修孔接地系统连接。A70mm2minimumgroundingconductorshallbeinstalledtheentirelengthofallpowerandcontrolcabletrays.Thisgroundingconductorshallbeboltedtoeachtraysection.ThetraygroundingsystemshallbeconnectedatseverallocationstotheFacilitymaingroundinggrid.ThesegroundingsystemconnectionsshallprovideameansofgroundingallequipmentandcabinetsintheFacilityandalloutlyingstructuresservedbythecabletraysystem,aswellasprovidingadirectpathtogroundintheeventofafault.应沿着所有动力和控制电缆桥架全长安装一个横截面至少为70平方毫米的接地导线。接地导线应通过螺栓与每个电缆桥架段连接。电缆桥架接地系统应在数个位置与设施主接地网连接。上述接地系统连接点应能够将设施和电缆桥架系统服务的所有外围结构内所有设备和机柜接地，并在发生故障时提供直接接地路径。Allconduitsenteringcabletraysshallbebondedtothetraybytheuseofbondingjumpersorgroundingbushings.Attheotherendzallconduitsshallbebondedtotheenclosureorequipmentbeingservicedviabondingjumpersorgroundingbushingstotheequipmentorcabinetgrounding.所有进入电缆桥架的导管应使用搭接线或接地套管与电缆桥架结合。在另一端，所有导管应通过与设备或机柜接地连接的搭接线或接地套管与外壳或所服务设备结合。Eachmotor(whetherMV-ratedorLV-rated)shallbeelectricallyconnectedtotheswitchgear(orMCC)groundingbusviaagroundingwirewithinitspowercablefeeder.Allmediumvoltagepowercableshieldsshallbeterminatedattheirrespectiveswitchgeargroundingbuses.Allmediumvoltage-ratedmotorsshallhave70mm2minimumgroundingconductorrisersconnectedbetweentheirframesandthegroundinggrid.AllLV-ratedmotorsshallhavetheirframesconnecteddirectlytothegroundinggridwithdedicated35mm2minimumgroundingconductorrisers.每个电机（不论是中压或低压）应与开关设备（或马达控制中心）接地母线通过电力电缆馈线中的接地线实现电气连接。所有中压电力电缆包皮应在其各自开关设备接地母线处结束。所有中压电机应在其框架与接地网间用横截面至少为70平方毫米的接地导线竖管连接。所有低压电机应使其框架通过横截面至少为35平方毫米的指定接地导线竖管与接地网直接连接。AnindividualinsulatedgroundingcablerisershallberoutedfromthegroundingsystemdirectlytotheFacilityDCSsignalgroundbusforelectricalnoiseconsiderations.CablesizeshallbeinaccordancewiththeDCSmanufacturer'srequirements,butnolessthan35mm2.应从接地系统用一根绝缘接地电缆竖管直接与设施分布式控制系统信号接地母线连接，以减少电气噪声。电缆尺寸应满足分布式控制系统制造商要求，但是不得小于35平方毫米。Everythirdfencepostshallbeconnecteddirectlytothegroundinggrid.Adjacentfencesectionsshallbebondedtoeachotherwithmultiplegroundingjumpers.Allgatesandfenceopeningsshallbeprovidedwithmultiplegroundingjumperstomaintaingroundingcontinuity.每隔两根栅栏柱应与接地网直接连接一次。相邻栅栏段应使用多根接地跳线彼此相连。所有门及栅栏开口应配备多根接地跳线，以保持接地连续性。AnoverallFacilitygroundingsystemresistancetestshallbeconductedbytheContractoroncethegroundingsystemisinstalled;butpriortoFacilityequipmentstart-upandoperation.Thefallofpotentialmethodshallbeused.Theresistancetestmustverifythattheoverallgroundgridresistanceislessthanone(1)ohm;andthatthestepandtouchpotentialmagnitudesarebothwithintheallowablerangespecifiedbyIEEE.SeveralindividualgroundpointlocationsshallalsobetestedbytheContractorfortotalresistancetothegroundgridtoensurethatallequipmentbondingisadequateandeffectivethroughout.全厂设施接地系统电阻测试应由承包商在接地系统安装完毕后进行；但是上述测试必须在设施设备启动和操作前实施。应使用电位降方法进行测试。电阻测试必须验证整个接地网电阻小于一(工)欧姆；且跨步电压和接触电压强度均在电气与电子工程师协会规定的可容许范围内。此外，承包商还应测试数个独立接地点位置对接地网的总电阻，以确保所有相连设备数量充足且有效。