Patent ID: 8459946

Claim:
A horizontal-axis wind turbine comprising: a rotor having a hub and one or more blades; a pitch control mechanism for driving and controlling a pitch angle of each of said blades independently; wherein said hub and said blade are connected by an interposed section which can freely rotate around the pitch axis of said blade with respect to both said hub and said blade; and said pitch control mechanism includes: a hub-side interposed section drive unit that relatively rotates said interposed section with respect to said hub, and a blade-side interposed section drive unit that relatively rotates said blade with respect to said interposed section; a pitch control unit for controlling said pitch control mechanism, said pitch control unit being configured to control an angle of said blade around said pitch axis with respect to said hub whether controlling both or just one of said hub-side interposed section drive unit and blade-side interposed section drive unit for one blade; a hub-side interposed section angle sensor that detects an angle of said interposed section around said pitch axis with respect to said hub, and a blade-side interposed section angle sensor that detects an angle of said blade around said pitch axis with respect to said interposed section; wherein said pitch control unit is configured to control an angle of said blade around said pitch axis with respect to said hub whether controlling both or just one of said hub-side interposed section drive unit and blade-side interposed section drive unit, based on the detected value from said hub-side interposed section angle sensor and the detected value from said blade-side interposed section angle sensor.