Applications throughout the World - Hybrid Anisotropic Materials for Wind Power Turbine Blades - page 11

TABLE 1.2
Power.Turbine.Rating.(kW)

TurbineManufacturers RatedPower(kW)

South.West.Windpower 0.4,.1.0

Bergey 1,.5,.10

Atlantic.Oriented.Corp. 50

Northern.Power.Systems 100

Enercon 500,.850

Micon 600,.800

Bonus 600,.1000

Vestas 660,.850,.1650,.2000

Nordex 1000

Mitsubishi 600,.1000

of.steel.castings.for.large.turbines,.especially.the.blade.hub.units,.is.one.of.
the.manufacturing.challenges.
Material. fatigue. properties. are. an. important. consideration. in. wind. tur-
bine.design..During.the.expected.30-year.life.of.a.wind.turbine,.many.of.the.
components. will. need. to. be. able. to. endure. 4×10 8 . fatigue. stress. cycles.. The.
high.cycle.fatigue.resistance.is.even.more.severe.than.for.aircraft,.automotive.
engines,.bridges,.and.most.other.structures.

1.4.5 Components Development Trends

1.4.5.1 Rotor Blades

Speciic.development.trends.of.the.rotor.blades.are.discussed.below.
Most. rotor. blades. are. built. from. iber/glass/carbon. ibers.. As. the. rotor.
size.increases.for.the.large.machine,.the.percentage.of.carbon.iber.increases.
because.high.strength.and.fatigue.resistance.need.to.be.compensated.

1.4.5.2 Gear Boxes

Most.small.turbines.designed.so.that.batteries.can.be.changed.use.a.vari-
able.speed,.permanent.magnet,.and.variable.frequency.generator.connected.
to.a.rectiier.
As.high-power,.solid-state.electronics.are.improved,.larger.machines.are.
likely. to. use. AC-DC-AC. cycloconverters.. This. is. based. on. turbines. being.
developed. by. northern. power. systems. (100. kW),. and. in. some. commercial.
machines.
This.trend.will.increase.the.use.of.magnetic.materials.in.future.turbines..
Large.epicycle.gearboxes.used.in.ships.may.continue.to.be.the.drive.system.
for.some.large.turbines. 13