Environmental Engineering Reference
In-Depth Information
Pitch
Low-speed
shaft
Rotor
Gear box
Generator
Anemometer
Wind
direction
Controller
Brake
Yaw drive
Wind vane
High-speed
shaft
Nacelle
Yaw motor
Blades
Tower
FIGURE 2.2
Horizontal-axis wind turbine components.
WIND TURBINE COMPONENTS
Anemometer
—This device measures the wind speed and transmits wind speed
data to the controller.
Blades
—Wind blowing over the two or three blades causes the blades to lift
and rotate; they capture the kinetic energy of the wind and help the turbine
rotate.
Brake
—A disc brake can be applied mechanically, electrically, or hydrauli-
cally to stop the rotor in emergencies.
Controller
—The controller starts up the machine at wind speeds of about 8 to
16 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.
Gear box
—Gears connect the low-speed shaft to the high-speed shaft and
increase the rotational speeds from about 30 to 60 rotations per minute
(rpm) to about 1000 to 1800 rpm, the rotational speed required by most
generators to produce electricity. The gear box is a costly (and heavy) part
of the wind turbine, and engineers are exploring direct-drive generators that
operate at lower rotational speeds and do not require gear boxes.
Generator
—Usually an off-the-shelf induction generator that produces
60-hertz alternating-current electricity.
