Numerical study on the performance of a wave energy converter with three hinged bodies

Modeling and Validation of an Electrohydraulic Power Take-Off System for a Portable Wave Energy Convertor with Compressed Energy Storage

“…The former often employs tools such as computational fluid dynamics (CFD) or experiments, and the goals are to improve the efficiency of the buoy responding to the wave motion [4][5][6][7]. The latter usually focuses on improving the PTO's architectural features, such as the traditional single or multiple-step conversion types [8][9][10][11][12][13][14][15][16][17][18]. Single step conversion usually requires a linear electric generator, the advantage of which, is that the direct conversion eliminates the inter-step losses of a multiple-step conversion system [8].…”

“…Though the overall efficiency could be offset by the increased number of energy conversion steps, the architecture could utilize more complicated energy conversion schemes, such as multiple connected bodies to resonate to a particular band of wave frequencies [11,15], or the accumulators in hydraulic or pneumatic PTOs to absorb excessive pressure fluctuations for more consistent power output [13]. For this reason, traditional large-scale wave energy conversion facilities are often of multistage design [16][17][18]. However, since centralized wave energy conversion facilities are usually permanently deployed near shore [16,17] or require certain mooring equipment [18], the traditional large-scale WECs lack the ability of redeployment.…”

“…For this reason, traditional large-scale wave energy conversion facilities are often of multistage design [16][17][18]. However, since centralized wave energy conversion facilities are usually permanently deployed near shore [16,17] or require certain mooring equipment [18], the traditional large-scale WECs lack the ability of redeployment. Additionally, mitigating line losses could be a challenging engineering task for the long transmission distances (in the magnitude of several hundred kilometers) between the sensors and power hub.…”

Extracting wave energy while reducing hydroelastic response of very large floating structures

“…For the raft WEC-type attachment, CF decreases with respect to wave period. This may be because the motion of the auxiliary pontoon seems to be mainly dependent on the wave curvature [150] which generally decreases with respect to wave period. For the OWSC-type attachment, as the wave period increases, CF first increases and then decreases after reaching its maximum value.…”

“…• The behaviour of PTO systems is assumed to be linear in this study. This assumption has been widely adopted when analysing conceptual designs of WECs [44,150]. However, the actual behaviour of PTO systems may be nonlinear [89,90].…”