Torque of a Wind Turbine

The use of wind energy has grown constantly duringmany different configurations of wind turbines systems
the last 10 years. This has led to an increase ofthey all work in the same way. The available power
research and development of larger and moreoriginates from the mass ow of the moving air,
effective wind turbine in order to offer renewablereferred to as the wind speed. The transformation to
energy to the customers . This has also lead to, as themechanical torque is done by aerodynamical forces
sizes of the systems increase, that controlling of windacting on the rotors blades, the actuator disc. The wind
turbines are beginning to be more flexible and alsoturbine shaft then transports the power to the
crucial.generator which is connected to the electrical grid.
The future promises a further increase in the use ofUsually there is a gearbox between the slowly rotating
control systems as new designs investigate controllingturbine shaft and the more rapidly rotating generator
load and power excursions by using variable speedshaft.
operation, and also aerodynamic controls and otherAs the incoming wind contains the energy input to the
devices in more complex schemes.system, the power output is dependent on the wind
Early modern-era wind turbines used passive bladespeed. A lowest and highest wind speed, WScutin
controls to regulate power, yawing and rotor braking.respectively WScutout, determines the range in which
As the size of turbines and the knowledge ofwind turbine can operate.
automation control systems increased, other passiveThe aerodynamics behavior of the wind turbines is
devices became impractical and active controldescribed with mass ow rate which must be the
systems arose. Today a 1-2 MW wind turbine oftensame everywhere within the stream-tube. When
has active pitch control.kinetic energy is extracted from the wind at the
The wind turbine is a device for conversion of kineticactuator disc it slows down its velocity.
energy in the wind into electricity. Although there are