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1、InsidetheWindTurbineAnemometer:Measuresthewindspeedandtransmitswindspeeddatatothecontroller.Blades:Mostturbineshaveeithertwoorthreeblades.Windblowingoverthebladescausesthebladesto"lift"androtate.Brake:Adiscbrake,whichcanbeappliedmechanically,electrically,orhydraulicallytostopther
2、otorinemergencies.Controller:Thecontrollerstartsupthemachineatwindspeedsofabout8to16milesperhour(mph)andshutsoffthemachineatabout55mph.Turbinesdonotoperateatwindspeedsaboveabout55mphbecausetheymightbedamagedbythehighwinds.Gearbox:Gearsconnectthelow-speedshafttothehigh-speedshafta
3、ndincreasetherotationalspeedsfromabout30to60rotationsperminute(rpm)toabout1000to1800rpm,therotationalspeedrequiredbymostgeneratorstoproduceelectricity.Thegearboxisacostly(andheavy)partofthewindturbineandengineersareexploring"direct-drive"generatorsthatoperateatlowerrotationalspee
4、dsanddon'tneedgearboxes.Generator:Usuallyanoff-the-shelfinductiongeneratorthatproduces60-cycleACelectricity.High-speedshaft:Drivesthegenerator.Low-speedshaft:Therotorturnsthelow-speedshaftatabout30to60rotationsperminute.Nacelle:Thenacellesitsatopthetowerandcontainsthegearbox,low-
5、andhigh-speedshafts,generator,controller,andbrake.Somenacellesarelargeenoughforahelicoptertolandon.Pitch:Bladesareturned,orpitched,outofthewindtocontroltherotorspeedandkeeptherotorfromturninginwindsthataretoohighortoolowtoproduceelectricity.Rotor:Thebladesandthehubtogetherarecall
6、edtherotor.Tower:Towersaremadefromtubularsteel(shownhere),concrete,orsteellattice.Becausewindspeedincreaseswithheight,tallertowersenableturbinestocapturemoreenergyandgeneratemoreelectricity.Winddirection:Thisisan"upwind"turbine,so-calledbecauseitoperatesfacingintothewind.Othertur
7、binesaredesignedtorun"downwind,"facingawayfromthewind.Windvane:Measureswinddirectionandcommunicateswiththeyawdrivetoorienttheturbineproperlywithrespecttothewind.Yawdrive:Upwindturbinesfaceintothewind;theyawdriveisusedtokeeptherotorfacingintothewindasthewinddirectionchanges.Downwi
8、ndturbinesdon'trequireayawdrive,thewindb
