How is Governing Executed in Wind Mills?

[ank160]

I want to know that how is govering is executed in case of wind mill to ensure that generator's shaft rotates at constant speed so as to generate electricity at fixed frequncy. Like in case of hydroturbine, governing is done by regulating water flowrate.

 

[EinsteinKillr]

I don't know if this is case in Wind Turbines, but I know in some generators that a flywheel and clutch mechanism is used to regulate rotational speed. The flywheel stores potential energy from the spinning turbine (or motor in the case of the generator) on which a clutch is installed so that the motor cannot spin the flywheel faster than a given speed. The flywheel in turn can continue to rotate at a given frequency even if the speed of the turbine is lower than needed for a given period of time based on its mass. Like I said, this may not be the case here, but it is a engineering trick used in generators.

 

[sophiecentaur]

Do they not just vary the pitch of the blades? A clutch would waste energy.