A novel magnetic bistable device (MBD) is proposed to improve the efficiency of energy harvesting of a point absorber wave energy converter (WEC) by decreasing the potential barrier of the bistable energy absorber. The novel MBD is mainly composed of two pairs of coaxial permanent magnet rings with different sizes. For the permanent magnet rings, one pair has the same magnetic field direction to provide negative stiffness and the other magnet rings have nonlinear positive stiffness property with a reverse magnetic field direction. The nonlinear dynamic model is established by adopting the state space model approach during solving the convolution integral of radiation force. The capture width ratio of the WEC with the novel MBD is studied with the change of design parameters in regular wave. Then the effect of structural parameters for the novel MBD on the wave energy capture ratio is discussed. The results indicate that using the novel MBD can significantly improve the performance of point absorber WEC especially under low wave excitations in comparison with that of the WEC with traditional MBD.

提出了一种新型的磁性双稳态器件（MBD），以通过降低双稳态能量吸收器的势垒来提高点吸收器波能量转换器（WEC）的能量收集效率。新型MBD主要由两对不同尺寸的同轴永磁环组成。对于永磁环，一对具有相同的磁场方向以提供负刚度，而另一对磁环具有非线性正刚度特性，且磁场方向相反。在求解辐射力的卷积积分时，采用状态空间模型方法建立了非线性动力学模型。利用规则波中设计参数的变化，研究了带有新型MBD的WEC的捕获宽度比。然后讨论了新型MBD的结构参数对波能捕获率的影响。结果表明，与传统MBD相比，使用新型MBD可以显着改善点吸收器WEC的性能，尤其是在低波激发下。