高性能多方向双圆弧形压电能量收集系统

High performance multi-directional dual circular piezoelectric energy harvester

为了解决传统压电能量收集系统通频带窄、功率密度低的问题,本文采用线性多模态共振法,提出一种双圆弧悬臂梁内外反向拼接的压电能量收集系统。两根梁上各覆盖一个压电层,压电层之间串联连接。建立二自由度系统集总参数模型和机电耦合模型来分析频率响应和输出性能。对比压电层弧度不同的压电能量收集系统的输出性能,根据测试结果,当弧度为0.5π时输出性能最佳。设置激励加速度为0.1 g,一阶模态下,谐振频率为82.19 Hz,开路电压为49.65 V,最大输出功率为3.74 mW;二阶模态下,谐振频率为119.14 Hz,开路电压为44.74 V,最大输出功率为3.54 mW。测试结果表明,该结构可有效拓宽通频带宽度至52 Hz,且功率密度高。该压电能量收集系统结构简单易于制备,工作频带宽,可在频率波动大的环境下供电,同时体积小、功率密度大,能在多方向激励下高效率收集能量,可应用于可穿戴设备、低功率设备等多个领域。

To solve the problems associated with the narrow bandwidth and low power density in conventional piezoelectric energy harvesters,a piezoelectric energy harvester with dual circular cantilever beams spliced inside and outside the inverse direction is designed with the linear multimodal resonance method.Each of the two beams is covered with a piezoelectric layer and the piezoelectric layers are connected in series.A two-degree-of-freedom system lumped parameter model and an electromechanical coupling model are studied to analyze the frequency response and output performance.The performance of the piezoelectric energy harvester is assessed with different radians of the piezoelectric layers,achieving optimal output performance when the radian is 0.5π.Setting the excitation acceleration at 0.1 g,the resonant frequency is 82.19 Hz,the open-circuit voltage is 49.65 V,and the maximum output power is 3.74 mW in the first-order mode.The resonant frequency is 119.14 Hz,the open-circuit voltage is 44.74 V,and the maximum output power is 3.54 mW in the second-order mode.The measured results show that the structure can effectively broaden the bandwidth to 52 Hz with high power density.This piezoelectric energy harvesting system is simple in structure,easy to manufacture,wide in a working frequency band,and can supply power in the environment with large frequency fluctuation.Meanwhile,it has the advantages of small volume,high power density,and high-efficiency energy collection under multi-directional excitation.Therefore,this system can be applied to many fields,such as wearable devices,low-power devices,and so on.