Conceptual design and analysis for a novel parallel configuration-type wave energy converter.

Oscillating body wave energy converter (OBWEC) is an essential way to exploit wave energy. Existing OBWECs with a single degree of freedom (DOF) suffer from a low energy conversion ratio. Although this power generation limit of OBWECs can be alleviated by increasing DOF, for the multi-DOF OBWEC, specific structure design guidelines, accurate energy conversion modeling and economic cost-related performance analysis at the conceptual design stage are still missing. To address this gap, this study proposes a novel parallel configuration WEC (PCWEC) with the idea of combining the advantages of multi-DOF OBWEC and parallel structure. The PCWEC energy conversion model is established under irregular wave states. Furthermore, we propose an energy cost-efficiency indicator and perform the performance comparison analysis and simulation experiments. Compared with typical OBWECs, results validate that the proposed PCWEC has the following advantages: (i) a significant power generation increase under the same device scale, (ii) greater optimal output power by power take-off control, and (iii) higher energy cost-efficiency under changing wave states. Such a novel PCWEC design concept improves the current OBWEC's power generation performance and application prospect and offers certain guidance for the future commercial development of OBWECs. [ABSTRACT FROM AUTHOR]