Patent ID: 9574457
Date: 2017-02-21
CPC Classifications: F01D,F05B,G01M

Claim:
1. A method for controlling a wind turbine comprising a wind turbine blade extending along a longitudinal axis from a root end to a tip end of the wind turbine blade, where the wind turbine blade has a root region, a transition region, and an airfoil region, the method comprising the steps of: a) obtaining a first sensor set signal indicative of a first bending moment at a first sensor position different from the tip end along the longitudinal axis of the wind turbine blade, b) obtaining a second sensor set signal indicative of a second bending moment at a second sensor position along the longitudinal axis, c) estimating a bending moment at a first estimation position along the longitudinal axis based on the first sensor set signal, wherein the first sensor position is different from the first estimation position along the longitudinal axis, wherein the estimation is carried out for the first estimation position being located at the root end of the wind turbine blade, and wherein the estimation is carried out by comparing the first bending moment and the obtained bending moment from step b) or assuming a zero bending moment at the tip end, to an approximation function indicative of the moment distribution along the longitudinal axis of the blade, d) transmitting a calculated bending moment to a control system of a wind turbine, and e) controlling the wind turbine blade via the control system by adjusting one or more operational parameters of the wind turbine blade based on the calculated bending moment.