is pitch control decided by power output or wind speed

Wind & Water Controls
1

Hi guys,

When we talk about pitch control, we assume only if wind speed is larger than rated wind speed then mechanical power output could be larger than rated power output. Capture.PNG
However, considering wind speed is measured at hub height and wind speed at top and bottom of blade differ in direction and speed, wind power actually is much more complicated than formula 1/2rhoarea*v^3. I am wondering if it is possible when wind speed is still smaller than rated speed, the power output is already larger than rated power output. If so, then this might generate electrical power above limit value, which will harm generator. Under this condition, should pitch control still be decided by wind speed or by power output? Many thx in advance for your response.

Sincerely,
Yanda

2

Dear Yanda,

It is rare for the pitch controller to use a direct wind speed measurement in its feedback loop. Using the generator speed and/or electrical power is more common. The wind at hub height does not determine the control region.

Best regards,

3

Thx, Jason. That makes sense. So the ideal power curve of wind turbine is only used to evaluate system condition of large scale renewable integration, right?

4

Dear Yanda,

There are multiple uses for a power curve, but what you state is one of them. The power curve you show is really an averaged quantity.

Best regards,

5

Thx, Jason. I appreciate your help on weekends.