Research on Optimal Power Capture Strategy of Dual-port Direct-drive Wave Energy Converters

The single-port direct-drive wave energy converters (SPDDWECs), consisted of single linear electrical generator, has widely applied oceanic wave energy converters (WECs) system. In order to overcome the discontinuity of electrical energy transmission in SPDDWECs due to the intermittent nature of waves. This paper presents a dual-port direct-drive wave energy converters (DPDDWECs), consists of dual-translators connected by electromagnetic springs. The analysis shows that the performance of the DPDDWECs much depend on the motion relationship between the dual-translators and the optimal frequency point (OFP). For this reasons, the motion relationship is analyzed according to the dynamics. By controlling the electromagnetic spring coefficient, the DPDDWECs can also output power continuously when the vertical velocity of the wave remains zero. The OFP is selected according to the two-degree-of-freedom optimal power principle. Simulation results show that the OFP can capture more power compared with the spectral peak frequency point which used in most researches.