Design Wind Power Turbine - Hybrid Anisotropic Materials for Wind Power Turbine Blades - page 16

passive.load.attenuation,.and.active.controls,.it.is.estimated.that.this.magni-
tude.of.blade.growth.can.be.achieved.in.combination.with.a.modest.system.
cost.reduction.
For.many.reasons,.hybrids.that.are.a.combination.of.glass.iber.and.carbon.
have.more.advantages.for.strength.in.wind.turbine.blades. 1

2.2 NewDesignConcept

The.new.design.concept.for.the.base.of.a.wind.tower.that.will.increase.power.
in.one.station.two.to.three.times.is.by.installation.of.30.to.50.machines.with.
propeller.blades..Each.station.of.wind.blades.has.its.own.drive.shaft,.which.
connects. to. a. generator.. The. shaft,. using. miter. and. bevel. gears,. drives. the.
rotation.of.the.blades.
Technology. is. intended. to. achieve. higher. elevations,. where. the. wind.
resource. is. much. greater,. or. to. access. extensive. offshore. wind. resources..
Modern. wind. turbines,. which. are. currently. being. deployed. around. the.
world,.have.three-bladed.rotors.with.diameters.of.70.to.80.m.mounted.atop.
60-.to.80-m.towers,.as.illustrated.in.Figure 2.1..Nacelle.enclosures.includes:.
low-speed.shaft,.gearbox,.generator,.1.5.MW,.and.electrical.control.
Typically. installed. in. arrays. of. 30. to. 150. machines,. the. average. turbine.
installed.in.the.United.States.in.2006.can.produce.approximately.1.6.mega-
watts.(MW).of.electrical.power..Rotating.the.blades.around.their.long.axis.
to.change.the.angle.of.attack,.with.respect.to.the.relative.wind.as.the.blades.
spin.around.the.rotor.hub,.controls.turbine.power.output..This.is.called. con-
trolling the blade pitch .. The. turbine. is. pointed. into. the. wind. by. rotating. the.
nacelle.around.the.tower..This.is.called. controlling the yaw ..Wind.sensors.on.
the. nacelle. tell. the. yaw. controller. where. to. point. the. turbine.. These. wind.
sensors,. along. with. sensors. on. the. generator. and. drive. train,. also. tell. the.
blade.pitch.controller.how.to.regulate.the.power.output.and.rotor.speed.to.
prevent. overloading. the. structural. components.. Generally,. a. turbine. will.
start. producing. power. in. winds. of. about. 5.36. m/sec.. and. reach. maximum.
power. output. at. about. 12.52. m/sec.. to. 13.41. m/sec.. The. turbine. will. pitch.
or. feather. the. blades. to. stop. power. production. and. rotation. at. about. 22.35.
m/sec..Most.utility-scale.turbines.are.upwind.machines,.meaning.that.they.
operate.with.the.blades.upwind.of.the.tower.to.avoid.the.blockage.created.
by.the.tower.
The.amount.of.energy.in.the.wind.available.for.extraction.by.the.turbine.
increases.with.the.cube.(the.third.power).of.wind.speed..Therefore,.a.10-per-
cent.increase.in.wind.speed.creates.a.33-percent.increase.in.available.energy..
A.turbine.can.capture.only.a.portion.of.this.cubic.increase.in.energy,.though,.
because. power. above. the. level. for. which. the. electrical. system. has. been.
designed,.referred.to.as.the. rated power ,.is.allowed.to.pass.through.the.rotor.