Abstract: A method for determining the wind speed or the wind direction experienced by a wind turbine such that a wind turbine setting such as an inflow angle error may be adjusted based on the determined wind speed or wind direction is defined, wherein a single airflow sensor is used together with a position sensor such as an accelerometer so that the value of the single airflow sensor at a previous position of the rotor may be warped and used together with a value of the single airflow sensor of a current position.

Abstract: The invention regards an apparatus for adjusting the yaw of a wind turbine adapted for mounting on a wind turbine comprising, a system for measuring the wind direction adapted, via a control signal, to control the yaw angle of the wind turbine based on the wind direction, and a wind sensor system adapted to determine the yaw error of the wind turbine, and means for modifying the control signal based on the yaw error determined by the wind sensor system.

Abstract: The invention regards a method for controlling the pitch angle of at least one wind turbine blade in a rotor connected to a main shaft on a wind turbine, the method comprises the steps of determining; a first component of the wind vector which is upwind, horizontal and aligned with the main shaft direction and, a second component of the wind vector which is upwind, perpendicular to the first component of the wind vector, wherein the first component of the wind vector and the second component of the wind vector are determined by use of at least one ultrasonic sensor mounted on the rotor, whereby the pitch angle is controlled based on the first component of the wind vector and the second component of the wind vector.