Receding-Horizon Pseudo-spectral Control of Wave Energy Converters Using Periodic Basis Functions

摘要: Power-maximizing control of wave energy converters (WECs) can be implemented within a receding-horizon (RH) framework, whereby the reference force or velocity trajectory is updated in real-time by feed-forward (FFC) algorithm. For computation optimal WEC trajectories and forces, Fourier pseudo-spectral (PS) control, using periodic basis functions, simple computationally attractive, for both linear non-linear dynamics. However, finite-length excitation signal, as seen FFC, general non-periodic. In this paper, it shown that, despite non-periodicity input PS method successfully used an FFC algorithm, applying suitable windowing functions to signal when necessary. Furthermore, forecasting algorithm introduced, solely based on past values excitation, impact forecast errors controller performance investigated. Overall, with without errors, proposed approach allows power absorption above 99% optimum, horizon less than 30 s model, 15 s model including quadratic viscous drag term.