Although various wave energy converters have been designed and deployed, the overall efficiency of wave energy absorption remains relatively low. Implementing control to WEC is an effective approach to enhance energy capture efficiency, which, however, requires information about future waves, thus making wave energy control a non-causal problem. To address this, a real-time implementable control approach is developed in this study for a point absorber wave energy converter, aiming to enhance power capture efficiency. The method constructs a causal approximation of the complex-conjugate control law, enabling the estimation of the target buoy velocity directly from the present wave excitation force allowing for sub-optimal regulation of buoy motion without relying on future wave information. Moreover, the proposed control scheme aims to approximate optimality across the full frequency range by incorporating frequency-dependent weighting, rather than targeting a single dominant component. In contrast to both the uncontrolled scenario and the peak-focused control method derived from the spectral maximum, this approach ensures broader spectral effectiveness. the proposed causal complex-conjugate control, which considers each frequency in the wave spectrum, demonstrates a significant enhancement in wave energy capture.
Chen et al. (Sun,) studied this question.