Methods and systems for alleviating loads in off-shore wind turbines

摘要

Control methods and systems of a wind turbine belonging to an off-shore wind park that use, in case of malfunction of the load measuring system, one of the following pitch vectors for the calculation of the individual pitch command of each blade:
- the pitch vector being applied at the same time in one wind turbine of the wind park where the load measuring system works properly
- a mean value of the pitch vectors being applied at the same time in a group of wind turbines of the wind park where the load measuring system works properly;
- the pitch vector resulting from a control law, obtained from historic records of the wind turbine when the load measuring system worked properly, defining the pitch vector as a function of at least the wind speed V, if the former pitch vectors are not available.