The current trend in the design of wind turbines is to increment the length of the blades in order to increase the annual power production, by means of a compromise between lightness and rigidity. One of the greatest problems related to this is a higher flexibility of the blade, which in combination with an increase in wind speed causes a greater deflection of the blades in the direction of the wind, with the consequent risk of collision between the blade tip and the tower. Several strategies have been developed in the state of the art that solve the problem (tilt angle modification, cone angle modification, thrust reduction with dynamic fine pitch), but all of them imply a reduction in the annual energy production. In an attempt to solve this energy loss, some strategies have been developed (as is the case of the strategy here explained, IPTCA) whereby the blade pitch angle is modified cyclically for each blade exclusively in a sector of rotation where the blade passes in front of the tower.
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