Model-based control of wind turbines: look-ahead approach

Artikel i vetenskaplig tidskrift, 2012

A new composite turbine control architecture that consists of feedforward and feedback parts based on the upwind speed measurements and wind speed measurements at the turbine site, respectively, is described. The algorithm starts with preprocessing of a low-rate sampled upwind speed via the spline interpolation method. A run-ahead model driven by the signals from a preprocessing block models the turbine response and produces the feedforward part of turbine controller. The turbine control system is driven by both the feedforward part that comes from the run-ahead model and feedback part based on the wind speed measured at the turbine site. It is proved that the controller is stable despite the difference between the time-shifted preview measurements (expected wind speed) and the actual wind speed measured at the turbine site. Existing industrial proportional-integral-derivative turbine controllers can easily be upgraded with the preview part of the control architecture described in this article. Improved blade load regulation via the blade pitch angle control guarantees a hard upper bound on the flapwise bending moment. The results are confirmed by simulation with a wind speed record from the Hono turbine outside Gothenburg, Sweden.