Patent ID: 9518560
Filing Date: 2016-12-13
CPC Classification: F03D,Y02E

Claim Text:
1. A method to individually optimize respective pitch angles of a plurality of blades in a wind turbine, the method comprising: a) supplying a modulation signal having a predefined modulating frequency to modulate at the modulating frequency a pitch angle of only a respective one of the plurality of blades being presently optimized; b) filtering output power of the wind turbine subject to the modulating frequency to extract a power signal in a frequency spectrum comprising at least the modulating frequency; c) mixing the extracted power signal and a demodulation signal oscillating at the modulating frequency to generate a signal comprising a product of the extracted power signal and the demodulation signal; d) filtering the generated signal to remove at least the modulating frequency and extract a gradient signal effective to search a pitch angle estimate conducive to optimize output power of the turbine; and e) integrating the gradient signal to cause the gradient signal to converge towards a value indicative of an optimal pitch angle for the respective one of the plurality of blades being presently optimized.