Livre Power, Lda.

Junho 03 2011
Wind power varies with the intensity of the wind. This is usually measured on the Beaufort scale, which takes into account the effects of wind speed on the surrounding environment, smoke, trees, buildings, etc.. This scale ranges from 0 to 12, in the following table:

 

 

Scale

 

 

Wind

Average speed in Km/h

 

 

Description of effects

0

Calm

1

Smoke rises vertically

1

Breeze

3

Smoke shows wind direction

2

Light Breeze

9

SFeel the wind in the face, the leaves move

3

Bonny breeze

16

Leaves and twigs in constant agitation

4

Moderate breeze

24

Raises dust and loose papers

5

Fresh breeze

34

Stir shrubs with leaves

6

Strong breeze

44

Large branches in motion

7

Moderate winds

56

Stir whole trees

8

Fresh wind

68

Break, small tree branches

9

Strong wind

81

Minor damage to buildings

10

Temporal

95

Trees uprooted

11

Storm

110

Widespread damage

12

Hurricane

Above 121

Devastatio

 

Wind turbines must be designed to withstand high winds without damage. On the horizontal axis machines the problem is most pressing.
Some have passive protection systems, deviating a bit of wind direction or leaning back. Thus they continue to work but without reaching too high rotational speeds. When the wind strength decreases back to its normal position.
Others have braking systems that come into operation at very high speeds.
The most sophisticated automated systems that do have to vary the angle of attack of the blades, reducing aerodynamic drag to increase and thereby reduce the speed, etc..
Of course if the wind has very high intensities in the order of hundreds of km/h, as in hurricanes, there is no protection system that resists! In these situations, the power of nature destroys everything!
Take this opportunity to illustrate with a video of my turbine to be subjected to moderate and strong winds.

Arménio Carreira às 17:42

www.aerogeradores.pt
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