Windsail turbine technicaladvantagesWord下载.docx
- 文档编号:4771732
- 上传时间:2023-05-04
- 格式:DOCX
- 页数:16
- 大小:462.65KB
Windsail turbine technicaladvantagesWord下载.docx
《Windsail turbine technicaladvantagesWord下载.docx》由会员分享,可在线阅读,更多相关《Windsail turbine technicaladvantagesWord下载.docx(16页珍藏版)》请在冰点文库上搜索。
Someoftherequirements:
Theunitmustbenearlysilent.(Teststodateconfirmthatwemetthisgoal.)
Theunitshouldnotkillbirds(howeverwecan’tavoidthosecommittingsuicideinthematingseason.)
Theunitshouldbecosteffective.(Studiesshowthatinmassproductionwecanmeetcostgoals.)
Theunitshouldmakesenseindistributedpowerapplication:
(Thisisanelusiverequirementthatchangesfromsitetosite,andwiththeprospectivebuyer.Howeverbasedonthecontinuedinquiriesfrompotentialcustomerswebelievewecanserviceasignificantsegmentofthemarket.)
Implications:
Tocapturepowerfromlowerwindspeedstheairfoilsneedtobehighlyefficient,theturbineneedstobeself-starting;
theairfoilsneedtobeabletoextractpowerastheycutacrossthewindinbothdirectionsoverawiderangeofangles.Theturbineneedstodealwithvariablewinddirections.
TheaerodynamicsspecialistsatMSRCspentagreatdealofeffortcalculatingvariousbladeshapes,computermodelsweremade,thenbladesegmentswerefabricatedfortestinginthehydrodynamicsfacility.Theresultisaspecificbladeshapethathasbeendefinedforapatentapplication.Thefollowingarephotosofbladesegmentsatthehydrodynamicsfacility.
Sincemostpeopleliveinareasofclassthreewindconditionsorless,wedeterminedthat,inareaswherepeoplelive,peakwindspeedsoccurlessthan1.5%ofthetime.Buildingawindmillsystemtocapturetheserelativelyrarepeakpowermomentsgreatlyincreasesthecostofthesystem,withoutgreatbenefittotheusers.Belowareexamplesofwindspeeddistributionsinspecificlocations.
Fromamathematicalpointofview,duetotheincreaseinpowerasthecubeofthewindvelocity,the1.5%ofthetimewithhighwindspeedsrepresentsasignificantportionofthetotalwindpoweravailableoverthecourseoftheyear.Howeverbuildingasystemtocaptureandusethispeakpowerisnotpractical.Tomakethispointunderstandable:
Awindmillinahurricanecanproducemorepowerduringthehurricanethanitcouldduringtherestoftheyear.Soifoneusedonlypowerproductionasameasurement,weshouldbuildwindmillstocapturepowerfromhurricanesandignoretherestofthewind.
Intherealworld,wefindthatwhilepowerproducerswanttomaximizetheamountofpowerproducedandsold,theusersofpoweraremoreinterestedinhavingsmalleramountsofpoweronamorereliablebasis.Thuswindfarmswithlargeturbinesoperatedforpowersellershaveaverydifferentsetofeconomicsthanpowerconsumers,particularlyconsumersofoffgridpower.
Tocapturesmalleramountsofpowerwithgreaterfrequency,itisnecessarythatthewindturbinebeself-startinginverylightwindconditions.Toaccomplishthisrequiresacombinationoffactors;
theairfoilsmustbeofthecorrectshape,theymustbeplacedinthecorrectposition,thebearingfrictionmustbeverylowandthealternatormustnotpresentresistanceuntilafterthesystemisataworkingspeed.
ThedirectlydrivenalternatordesignedbyEmpireMagneticsInc.hasnoswitchedironinthemagneticcircuit,sounlikeotherpermanentmagnetalternators,thisdesignhaszerocogging,presentingnearzerostartingresistance.Inadditionthereisnomagneticattractionorloadsplacedonthebearinguntilpowerisbeingconsumedfromthealternator.Thesetwofactorsallowtheturbinetobeginturninginverylightwindconditions.Byusingalargediameterdirectdrivealternatordesignweeliminatelossesandcostsassociatedwithgearsorothermechanicaldrivesystems.Sincewehavenoswitchedironinthemagneticsystem,itisfeasibletousethestructuralironofthewindmillascomponentsinthemagneticdesign;
thisintegrationallowscostreductionsnotpossiblewithotheralternatordesigns.
Forthosenotacquaintedwiththeelectricmotor/alternatorindustryitiseasytotaketheavailabilityofasuitablealternatorforgranted.Howeverthisismostdefinitelynotthecase.Thereareveryfewpeoplewiththetechnicalskillsneededtodesignasuccessfulalternator.Thereareevenfewercompanieswiththeresourcestomanufacturethesedesignsinaneconomicmanner.Thecompaniesthatareintheelectricmotorbusinesstendtobelarge,andtheyarefocuseduponmanufacturedproductsthatprofitablyloadtheirexistingfactories.Windmillcompaniesthatapproachthemotormanufacturingcompanieswillbepresentedwiththemotorproductsthatareavailablefromtheproductionlines.Theseproductsareillsuitedtowindpowerapplications.
Integrationofthealternatorintothewindturbineassemblyisagreatwaytocutthecostofthewindmill.Howeverdoingsochangesnearlyeverythingtheelectricmotormanufacturingcompanydoesorprovides.Thereforeunlessthemotorcompanyhappenstoownthewindmillcompanytheyhavelittleincentivetocooperateinthedevelopmentofsuitablealternatordesigns.ItisnotanaccidentthatGeneralElectricandSimensarebothelectricmotormanufacturingcompanies,andproducersoflargewindmills.
Severaldifferentsmallwindturbinecompanies,eachinthestartupmode,haveapproachedEmpireMagneticsInc.,seekingcosteffectivealternativestoavailableofftheshelfalternatorproducts.Havingworkedwiththesestandardalternatorproductstheyfind:
Thespeedrangeofthemotorsisnotmatchedtothewindturbinewhichrequiresgearingorothermechanicaladaptationswhichincreasecomplexityandcostwhilereducingefficiencyandreliability.Thevoltagefactorsofthestandardmotorsarenotinthecorrectrange,thepolecountsaretoolow,thepowerfactorsaretoohigh,magneticcoggingforcesaretoobig,theironinthemagneticcircuitcorrodesintheweather,themagneticforcesappliedtothebearingsshortenthelifeoftheturbine,andfinallythesmallcompanyhasnowaytoinfluencethecostofthealternators.Otherthanthateverythingisjustfine.
Photoofalternatormagnetsmountedtothehubofthewindturbine.
IntheWind-sailturbinedesign,themechanicalbearingsystemisplacedatthemiddleoftheassembly,wherethewindloadingonthetopoftheassemblyisapproximatelyequaltothatonthebottom.Thisarrangementinconjunctionwiththespecificbearingdesignresultsinverylowfrictioninlightwindconditions,exactlywhatweneededfortheintendedpurpose.
Aswescaleuptolargerturbinedesigns,thebearingsbecomemorecritical.Bearinglifeisdecreasedasthecubeoftheload,andthesquareofthespeed.Largerturbinesareheavierandbecausethediametersarelargerthesurfacespeedofthebearingisincreased.Toovercomethisproblemwehavedesignedpassivemagneticbearings.Suchbearingsarenotspeedlimited,theydonotwearout,andbasedonourdesigntheyarelessexpensivethanmechanicalalternatives.Theexactarrangementofthemagnetswebelievecanbepatented.FEAindicatesthemassofmagnetisreducedbyafactoroftwoascomparedtotheobviousapproach.Howeverthereisacompanythathaspatentedtheuseofmagneticbearingswithwindmills,andsoitwouldbenecessarytoreachanagreementwiththemforthecountrieswheretheyhavepatents.
AsthescientistsatMSRCfocusedontheexactshapeoftheairfoil,theydidextensivemathmodeling.Thiseffortresultedinhighefficiency,self-starting,bi-directionalairfoils,butalsoidentifieduniqueoperationalfeaturesasshowninthefollowinggraph.Thesefeaturesallowedustocreateacontrolsystemthatisspecifictotheturbineandbladedesign.Inthemiddleofthegraphisacurvedepictingthenon-lineareffectsonpoweroutputversusrotationalspeedoftheturbine,withrespecttothewindspeed.Thecontrolsystemtakesadvantageofthisfeaturetomaximizepoweroutputfromwindspeedsbelow3kw,butdeclinetogeneratepowerabove3Kw.Thissubtledistinctioniseasytomiss.Ifwedon’tgenerateextrapower,wedon’thavetheexpenseofdisposingofit.
Thewaytoobtainmorepowerinlightwindconditionsistomaketheturbinelarger,buttodosowithoutasignificantcostincrease.Fromtheoutsetweplannedtomaketheairfoilsbyalowcostmassproductionprocess,extrusionorpultrusionaretheobviouscandidates.Sowedesignedtheairfoilswithconstantcrosssectionsinordertoaccommodatealowcostmanufacturingprocess.Oncethemachinesaresetupandrunning,thebladecanbemadeinlongproductionruns,withsectionscuttolengthaftertheyexitthemachine.Thisfocusonamanufacturingprocessaswellasatechnicaldesigngivesustheflexibilitytomaketurbinebladesofdifferentlengthsatverylowcost.AllowingWind-sailtoprovidemorewattsperdollarinlightwindconditionsthanthecompetition.
Belowisaphotoofairfoilsandgraphicdepictingmanufacturingmethod.
Sinceourbladesarelowincosts,theturbineisarelativelylowcostcomponentascomparedtotherestofthewindpowersystem;
oversizingtheturbinetogatherwindpoweravailablemostofthetime,whenpeoplewantit,providesmorereliableandmoreusefulpower,withoutagreatcostpenalty.Howeveravoidingthecostassociatedwithcapturingthepeakpowerrequiresstrictmanagementdiscipline.Humannatureandtechnicalanalysisofmomentaryorevenannualpowerproductiontemptsmanydesignersintotryingtocapturepeakpower,itisonlywhenabusinessmindedmanagerplacescostconstraintsuponthetechn
- 配套讲稿:
如PPT文件的首页显示word图标,表示该PPT已包含配套word讲稿。双击word图标可打开word文档。
- 特殊限制:
部分文档作品中含有的国旗、国徽等图片,仅作为作品整体效果示例展示,禁止商用。设计者仅对作品中独创性部分享有著作权。
- 关 键 词:
- Windsail turbine technicaladvantages