CONTROL OF WIND TURBINES IN RESPONSE TO WIND SHEAR

摘要

A wind turbine is controlled in response to an estimate of vertical and/or horizontal wind shear. A tilt moment is estimated from flapwise and edgewise blade bending moments, azimuth and blade pitch positions and used to estimate vertical wind shear. A yaw moment is also estimated from flapwise and edgewise blade bending moments, azimuth and pitch position and used to estimate horizontal wind shear. A tip speed ratio is determined from an estimate of wind velocity over the rotor plane and is used to set a blade pitch angle which is passed to a blade pitch controller. The pitching may be collective or individual. In the latter case, the tip speed ratio is determined from a plurality of rotor plane positions to derive a cyclic pitch reference for each blade.

主权项

1. A method of controlling a wind turbine having a rotor and a plurality of rotor blades, comprising obtaining a wind speed value, determining blade loading comprising determining blade bending moments, estimating a component of vertical wind shear across the rotor plane from the wind speed value and an estimate of main bearing tilt moment derived from the blade bending moments, a measure of blade pitch and azimuth angle, determining the tip speed ratio from the wind speed value and the wind velocity over the rotor plane, selecting a curve of tip speed ratio against blade pitch angle based on the estimated vertical wind shear component, selecting a blade pitch angle based on the selected curve and the tip speed ratio, and adjusting the blade pitch in accordance with the selected blade pitch angle.