Yaw and pitch angles

摘要

Methods for determining a yaw angle and a pitch angle cycle for a wind turbine are disclosed. The methods comprise measuring during a measuring time a wind speed and a wind direction at a plurality of measuring heights between the maximum and minimum height at the wind site, determining an average wind speed and an average wind direction for each of the measuring heights during the measuring time, and determining a wind speed distribution and wind direction distribution between the maximum height and the minimum height, and determining one or more yaw-pitch combinations of yaw angle and pitch angle cycles as a function of an azimuth position of a rotor blade that lead to a desired angle of attack along the rotor swept area. The present disclosure further relates to methods of operating a wind turbine and suitable wind turbines.

主权项

1. A method of determining a yaw angle and a pitch angle cycle for a wind turbine located at a wind site, the wind turbine having
a support structure, a nacelle rotatably mounted upon the support structure, a generator and a system for varying a torque of the generator, a rotor with a plurality of blades defining a rotor swept area between a maximum height and a minimum height, and operationally connected with the generator, a pitch mechanism for each of the blades for rotating the blades around their longitudinal axes, determining pitch angles for the blades and having a maximum pitch speed, and a yaw system for rotating the nacelle around a longitudinal axis of the tower, the method comprising:
measuring during a measuring time a wind speed and a wind direction at a plurality of measuring heights between the maximum and minimum height at the wind site;determining an average wind speed and an average wind direction for each of the measuring heights during the measuring time;determining a wind speed distribution and wind direction distribution between the maximum height and the minimum height based on the average wind speed and average wind direction for each of the measuring heights and by assuming a wind speed distribution and wind direction distribution between the measured heights;determining a desired angle of attack cycle as a function of an azimuth position of a rotor blade along the rotor swept area for a representative portion of the blade based on the wind speed distribution;determining a yaw angle based on the wind direction distribution and taking into account the desired angle of attack cycle as a function of the azimuth position and the maximum pitch speed; anddetermining a pitch angle cycle as a function of the azimuth position of the rotor blade based on the desired angle of attack cycle and the determined yaw angle.