A Piezo-hydraulic Energy Harvester (PHEH) was presented based on solid-fluid coupling vibration to harvest low-frequency and high-level vibration energy, and its structure as well as working principle were introduced. With an established energy-conversion model, the influence factors on the piezo-hydraulic harvester were analyzed. The theoretic results show that the output performance of the PHEH depends on the vibration frequency/level, the structure and size of piezodisc/cylinder, liquid volume/performance, and system backpressure. The desired performance can not be achieved unless the above parameters are matched well. By a piezodisc with a diameter of 60 mm and a thick- ness of 0. 9 mm and a cylinder with a diameter of 16 cm and a length of 100 cm, a PHVI was fabricated and tested by taking water as liquid medium at different frequencies/backpressures/exciter-amplitudes. The test results suggest that there is an optimal vibration frequency (8 Hz) for the PHEH to achieve the maximal output voltage, which rises with the increasing of backpressure and vibration level. In the case of unvaried other parameters, the achieved voltage from the PHEH under 0 . 4 MPa is 1, 65 times that under 0 . 2 MPa.%提出一种基于流固耦合作用的压电液压振动俘能器来实现低频、高强度振动能量回收.介绍了浮能器的系统构成及工作原理并进行了理论及试验研究.理论分析结果表明,压电液压俘能器的性能是由环境振动频率/振动强度、液压缸/压电振子的结构性能参数、流体容积/特性以及系统背压(蓄能器预置压力)等多种要素共同决定的,仅当各要素配置合理时才能实现压电液压俘能器的预期功能.采用外径为60 mm、厚度为0.9 mm的双晶压电振子及外径为16 cm,长度为100 cm液压缸制作了试验样机,并以水为工作介质进行了不同频率/背压/激振器振幅条件下的试验测试.试验结果表明,存在最佳工作频率(8Hz)使压电液压俘能器输出电压最大,且输出电压随系统背压及液压缸振幅的增加而增加.其它条件不变时,0.4 MPa背压下的输出电压是背压0.2 MPa时的1.65倍.
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