动态多稳态压电风能俘能结构设计与实验验证

传统的线性颤振式风能俘能结构在变风速环境下转换效率不高.针对此问题,论文提出了一种动态多稳态颤振式压电俘能结构,可在较宽的风速范围内保持较高的电压输出.该结构在悬臂梁自由端有一矩形平板和一永磁体,并在梁自由端附近放置两个固定永磁体,磁铁间的磁吸力使结构具有两个静态稳定平衡位置和一个动态稳定平衡位置.为了验证所提出结构的优越性,加工了实验装置,开展了不同风速下风能转换效率的研究.发现当风速较小时,该结构具有双稳态特性;而当风速较大时,结构会出现新的稳定位置,变为三稳态系统.利用这种动态多稳态特性,可在很宽的风速范围内实现阱间跳跃并伴随高电压输出.实验结果表明,这种动态多稳态结构,当风速在2.0 m/s-7.5 m/s区间变化时,能够激发并保持阱间跳跃,甚至相干共振.因此,该结构可在宽风速阈环境下保障电能的高效输出.

Design and experimental verification of dynamic multi-stable piezoelectric wind energy harvester

Aiming to overcome the inefficiency of flutter energy harvester for altering speed wind, a dynamic multi-stable flutter piezoelectric wind-energy-harvester was proposed in this paper. This harvester consists of a cantilever with a rectangular plate, three magnets and a piezoelectric patch. To prove the harvester’s superior performance in scavenging wind energy, a prototype was fabricated, and the validation experiment was carried out with the wind speed altering. The results show that the wind energy harvester exhibits the bi-stable characteristic for low wind speed; whereas it exhibits the tri-stable characteristic for high wind speed, in which case a neutral equilibrium position emerges and becomes stable gradually. The dynamic multi-stable harvester could execute snap-through and even coherent resonance for the wind speed ranging from v=2.0 m/s to v=7.5 m/s, thus it could generate a high output over the wide range of wind speed.