Читать книгу Wind Energy Handbook - Michael Barton Graham - Страница 104

Figure 3.58 shows the power curves for a turbine rated at 60 kW, which is achieved at 12 m/s. At wind speeds below the rated level, the blade pitch angle is kept at zero degrees. As rated power is reached, only a small negative pitch angle, initially of about 2°, is necessary to promote stalling and so to limit the power to the rated level. As the wind speed increases, small adjustments in both the positive and negative directions are all that are needed to maintain constant power.

The small size of the pitch angle adjustments make pitching to stall very attractive to designers, but the blades have the same damping and fatigue problems as fixed‐pitch turbines.