WIND TURBINE

A wind turbine converts the kinetic energy in the wind into mechanical power. We use a generator to convert mechanical energy in electricity.

  • Depending on the technology, the blades of the wind turbine turns revolution per minute.,at a variable velocity of the rotor.
  • whereas, velocity varies due to the velocity of wind in order to reach greater efficiency

Working and construction

wind turbine

  • Blowing air can turn the wings of turbine and electricity will generate from generator.

How does the blowing wind turns the wings?

  • The blade has a lots of airfoil cross section consisting of different size and shape from root to tip.
  • Airfoil technology make the wind turbine blades turn.
  • That means the  lift force is produced when a fluid moves over an airfoil.
  • In this way wind turbine receive a basic rotation .
  • The turning of wind turbine blade experience the wind relatively.(CONCEPT OF RELATIVE VELOCITY)

                             i.e V relative=V wind – V blade

  • Therefore,the wind turbine blade is position in a tilted mannered in order to align with the relative wind speed .
  • As the blade velocity increases to the tip the relative wind speed become more inclined towards the tip .
  • This means that a continous twist is given to the blade from root to tip.
GENERATOR
  • However this rotation cannot be directly coupled to a generator.
  • because the wind turbine blades typically turns at a very low rate at rpm due to issue of noise and mechanical strength.
  • Considering this low speed rotation we cannot produce any meaningful electricity frequency from a generator .the speed is increases in gear box .
GEARBOX
  • The gearbox use a planetary gear set arrangement to achive the high speed ratio.
BRAKE
  • A break also sits in a nacelle the function of brake is to arrested the wind blade rotation during excessively windy condition.
  • cut off speed≈ 80km/hr.
STEP-UP TRANSFORMER
  • Consequently the electricity  is passed through the cable towards the base of step up transformer .
  • The wind turbine should face the wind normally for max. power extraction .
  • but wind direction can change at any time.
VELOCITY SENSOR
  • A velocity sensor on the top of the nacelle measure the wind speed and direction .
  • The deviation in the wind direction is sent to an electronic controller .Further, to correct the error ,the appropriate signal is send to yawing mechanism.
YAWING MECHANISM
  • The yaw motor turn the nacelle
  • thus the turbine will always be align with the blow direction.
  • according to wind speed the relative velocity angle of the wind also changes
  • a blade tilting mechanism tilt the blade and guarantee a proper alignment of the blade with the relative velocity.
  • thus the blade are always at the optimum angle to attack with the relative wind flow.

 

 

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