KETEP 세계에너지시장정보

A method for reducing gear induced noise from a wind turbine, the wind turbine comprising a rotor, a generator (5) and a gearbox (3) interconnecting the rotor and the generator (5), the method being characterized by comprising the steps of: - during operation of the wind turbine, generating a first vibration map (18) specifying, for each of a plurality of operating points of the generator (5), a virtual phase of vibrations originating from gear tooth meshing of the gearbox (3), relative to a first reference phase, at the respective operating points, each operating point being defined by a rotational speed and a torque of the generator (5), - at a later point in time, operating the wind turbine and generating a second vibration map (19) specifying, for each of a plurality of operating points of the generator, a virtual phase of vibrations originating from gear tooth meshing of the gearbox (3), relative to a second reference phase, at the respective operating points, - identifying an overlap (22) between operating points of the first vibration map (18) and operating points of the second vibration map (19), - for at least some of the operating points within the identified overlap (22), comparing the virtual phase of vibrations of the first vibration map and the virtual phase of vibrations of the second vibration map, and deriving a phase offset between the first vibration map (18) and the second vibration map (19), based on the comparison, - adjusting the virtual phase of vibrations of each of the operating points of the second vibration map (19) by a value corresponding to the derived phase offset, so as to align the first vibration map (18) and the second vibration map (19, 20), - combining the first vibration map (18) and the second vibration map (19, 20) into a resultant vibration map (21), and - controlling operation of the generator (5) in accordance with the resultant vibration map (21).