直激式压电风能捕获器的性能分析与实验

提出一种由压电梁及其端部附加质量构成的直激式压电风能捕获器。在考虑了压电振子静平衡变形的基础上,根据涡激振动理论建立了柔性压电振子的自激振动理论模型并进行了仿真分析,获得了压电梁厚度比、附加质量及风速对其发电性能的影响规律。结果表明,存在最佳的压电梁厚度比使输出电压、电能及功率最大,电压/电能/功率所对应的最佳厚度比分别为0.5/0.65/0.65。其它参数确定时,存在最佳风速/附加质量使输出电压最大,且最佳风速随附加质量增加而降低、最佳质量随风速增加而降低。制作了风能捕获器样机并进行了试验测试,风速为4.8/7.2/10m/s时,对应的最佳附加质量及最大电压分别为15/11/7g和1.9/3.94/6.18V;风速为10m/s时,10g附加质量下的输出电压为0/20g附加质量下的4.1/1.2倍。结果证明根据实际风速范围确定合理的附加质量可提高发电能力。

Performance analysis and test of blowing-type PZT wind energy harvester

A blowing-type PZT wind energy harvester consisting of a piezo-cantilever and a proof mass on its free-end was presented. By considering the static balance deformation of the piezoelectric vibrator, an analysis model of a flexible piezoelectric vibrator was established and simulated on the basis of the theory of vortex-induced vibration. Then, the influences of thickness ratios, wind speeds and proof masses on the electrical energy generation were obtained. The results show that there are individual optimal thickness ratios for the generated voltage, energy and the output power to achieve peaks, and the optimal thickness ratios for the generated voltage/energy/power are 0.5/0.65/0.65, respectively. Under other parameters given, there are optimal wind speeds and optimal proof masses for the voltage to achieve their peaks, and the optimal wind speed (proof mass) decreases with the increasing of proof mass (wind speed). A PZT wind energy harvester was fabricated and tested under different proof masses and wind speeds. The experiment results show that the achieved optimal proof masses and optimal voltages under wind speeds of 4.8/7.2/10 m/s are 15/11/7g and 1.9/3.94/6.18 V respectively. In the case of wind speed of 10 m/s, the generated voltages under 10 g proof mass is 4.1/1.2 times those under 0/20g proof mass respectively. It concludes that a reasonable proof mass is helpful for a PZT wind energy harvester to generate more energies.