Combined wind turbine fatigue and ultimate load reduction by individual blade control

Han, Y and Leithead, W E (2014) Combined wind turbine fatigue and ultimate load reduction by individual blade control. Journal of Physics: Conference Series, 524 (1). pp. 1-10. 012062. ISSN 1742-6588 (https://doi.org/10.1088/1742-6596/524/1/012062)

[thumbnail of Han-Leithead-JPCS2014-Combined-wind-turbine-fatigue-and-ultimate-load-reduction]
Preview
Text. Filename: Han_Leithead_JPCS2014_Combined_wind_turbine_fatigue_and_ultimate_load_reduction.pdf
Final Published Version
License: Creative Commons Attribution 4.0 logo

Download (1MB)| Preview

Abstract

If each blade of the wind turbine has individual pitch actuator, there is possibility of employing the pitch system to mitigate structural loads through advanced control methods. Previously, considerable reduction of blade lifetime equivalent fatigue loads has been achieved by Individual Blade Control (IBC) and in addition, it has also been shown the potential in blade ultimate loads reduction. However, both fatigue and ultimate loads impact on the design and life of wind turbine blades. In this paper, the design and application of IBC that concurrently reduce both blade fatigue and ultimate loads is investigated. The contributions of blade load spectral components, which are 1P, 2P and edgewise mode from blade in-plane and/or out-of-plane bending moments, are firstly explored. Four different control options for reducing various combinations of these load components are compared. In response to the different spectral peaks of both fatigue and ultimate loads, the controller has been designed so that it can act on different frequency components which vary with wind speed. The performance of the IBC controller on fatigue and ultimate load reduction is assessed by simulating a 5MW exemplar wind turbine. Simulation results show that with a proper selection of controlling inputs at different wind speed, the use of a single combined IBC can achieve satisfactory reduction on both fatigue and ultimate loads.