K SAMEER AHMED (10J41A0220)
MAIN COMPONENTS OF HAWT
Low speed shaft
High speed shaft
Anemometer & Wind vane
ROTOR (BLADES & HUB)
– Main part which convert free flowing wind energy
to useful energy.
– Uses Lift & Drag principle as shown in the picture.
– Three blade rotor is best compared to two and
single blade turbines.
– In simple designs, the blades are directly bolted to
– In other more sophisticated designs, they are
bolted to the pitch mechanism, which adjusts
their angle of attack according to the wind speed.
– The hub is fixed to the rotor shaft which drives the
generator through a gearbox.
• LOW SPEED SHAFT
– The shaft from hub to the Gear box
– Speed is typically between 40rpm to
– Generators typically rotate at 1200rpm to
• GEAR BOX
•Gearbox increases the speed of
•Meets the requirement of the
• High Speed Shaft
– Gearbox is followed by the high speed
– Connects to generator
• Braking Mechanism
•A mechanical drum
brake or disk brake is used
to stop turbine in
•This brake is also used to
hold the turbine at rest for
– Wind power Generator converts wind
energy(mechanical energy) to electrical energy.
– Typically wind turbines generate electricity
through asynchronous machines that are directly
connected with the electricity grid.
– The Generator is attached at one end to the wind
turbine, which provides the mechanical energy.
– At the other end, the generator is connected to the
– The generator need to have a cooling system to
make sure there is no overheating.
– The controller starts up the machine at
wind speeds of about 8 to 16 miles per
hour (mph) and shuts off the machine at
about 55 mph.
– Turbines do not operate at wind speeds
above about 55 mph because they might
be damaged by the high winds
– The controller gets wind speed data from
the anemometer and acts accordingly .
• Yaw System
– The yaw system of wind turbines is the
component responsible for the orientation of the
wind turbine rotor towards the wind.
– It is the means of rotatable connection between
nacelle and tower.
– The nacelle is mounted on a roller bearing and
the azimuth rotation is achieved via a plurality of
powerful electric drives.
• Yaw system consists of
– Yaw bearing
– Yaw drives
– Yaw brake
• Yaw Bearing
– One of the main components of the yaw
system is the yaw bearing. It can be of the
roller or gliding type and it serves as a
rotatable connection between the tower
and the nacelle of the wind turbine.
• Yaw drive
– The yaw drive is used to keep the rotor facing into
the wind as the wind direction changes.
– The yaw drives exist only on the active yaw
systems and are the means of active rotation of
the wind turbine nacelle.
– Each yaw drive consists of powerful electric
motor (usually AC) with its electric drive and a
large gearbox, which increases the torque.
• Yaw brake
– In order to stabilize the yaw
bearing against rotation a means
of braking is necessary.
– One of the simplest ways to
realize that task is to apply a
constant small counter-torque at
the yaw drives.
– This operation however greatly
reduces the reliability of the
electric yaw drives, therefore the
most common solution is the
implementation of a hydraulically
actuated disk brake.
– Typically, 2 types of towers exist
• Floating towers and
• Land-based towers.
– Floating towers can be seen in
offshore wind farms where the
towers are float on water.
– Land-based Towers can be seen
in the Onshore wind farm where
the towers are situated on the
• For HAWTs, tower heights approximately two to
three times the blade length have been found to
balance material costs of the tower against
better utilisation of the more expensive active
• At the bottom level of the tower there will be
stepup transformers for the connection to the