Abstract
Advanced control strategies are necessary to maximize the energy harvest of Wave Energy Converter (WEC), and most of them require the knowledge of wave excitation force to determine the control input. However, the excitation force is a non-measurable quantity. The WECs deployed in arrays can achieve high economic value with important practical significance, but it also makes excitation estimation more complicated due to hydrodynamic interactions among devices. Estimation of wave excitation force based on the knowledge of all array devices is an effective approach to improve estimation accuracy with high computing requirements. In this paper, the novel local estimators for WEC array based on different communication graphs are presented, and their advantages are emphasized compared with independent estimators and global estimators. These estimators are applied to different array layouts, and additional sensitivity analyses are performed to evaluate the performance for various separation distances, wave directions, and measurement noises. This study shows that local estimators have higher estimation accuracy than independent estimators, improving up to 216.3% computational efficiency of global estimators. Proposed local estimators can provide an available method to trade off estimation accuracy and computational efficiency, which is of great significance for the estimator design of WEC array.