Enhancing efficiency of a point absorber bistable wave energy converter under low wave excitations

Recent advances in wave energy converters based on nonlinear stiffness mechanisms

“…Unlike a traditional linear mechanism, a bistable mechanism has a double-well restoring force potential with two stable equilibria and one unstable equilibrium (see Fig. 5) [45] . Because of Ref.…”

“…Δ Fig. 5 Potential energy curve and possible motion patterns for the bistable mechanism, where the solid black line denotes the typical profile of the potential energy for the bistable mechanism, and three other curves show possible trajectories for (a) the local oscillation within one well, (b) the chaotic oscillation between two wells, and (c) the periodic oscillation between two wells [45] (color online)…”

“…[27], [34]- [38], [40]- [45], [31], [47], [65]- [66] [32], [54] [39], [46], [49], [76] [48], [50]- [53], [55]- [64] Younesian and Alam [65] proposed a bistable mechanism with two rigid links and two oblique stiffnesses. By adjusting the geometric parameters of the bitable mechanism, this structure can be achieved in different multi-stable states from bistable to four-stable, and the potential barrier can be reduced by increasing the number of steady states.…”

“…In contrast to the multi-stable mechanism, some scholars have added an auxiliary stiffness device to the traditional bistable mechanism to directly reduce the barrier. Based on the traditional magnetic bistable mechanism proposed by Zhang et al [41] , Zhao et al [45] and Xi et al [55] proposed improved magnetic bistable mechanisms by adding auxiliary magnetic rings, as shown in Fig. 9.…”

“…8 Bistable X-structured electromagnetic WEC [57] Fig. 9 Improved magnetic bistable mechanisms: (a) structure with three pairs of magnetic rings [45] and (b) structure with two pairs of magnetic rings [55] (color online)…”