Point Absorber Ocean-Wave Energy Piezoelectric Harvester Using Impact Driven and Frequency Up-Conversion Mechanism

• Main Authors: Zeng-Hui Qiu, 邱增輝
• Other Authors: 吳嘉哲
• Format: Others
• Language: zh-TW
• Published: 2018
• Online Access: http://ndltd.ncl.edu.tw/handle/uyvt2b

碩士 === 國立中興大學 === 機械工程學系所 === 106 === In this study, a point absorber of a piezoelectric ocean-wave harvester was proposed. A point absorber is an ocean-wave harvester that have small dimensions relative to the incident wavelength and is able to absorb energy from all directions. Piezoelectric ocean-wave harvesters were developed by a frequency-up conversion mechanism and a lead zirconate titante (PZT) power generator. The frequency-up conversion mechanism included a rack, a large gear, two small gears and a cam and able to drive PZT power generator at multiplier frequency higher than incident wave. The rack was used to convert the incident wave motion to mechanical rotation. The gear group was used to increase the rotation speed and the cam was used to impact the PZT power generator. The PZT power generator include a fixed seat and 6 PZT cantilevers. PZT cantilevers were developed from sol-gel PZT thick films on silicon wafer. The 130-μm sol-gel PZT thick films is deposited onto bare Si/SiO_2/〖Si〗_3 N_4/Ti/Pt substrates via spin-coating. The developed point absorber of piezoelectric ocean-wave harvester was then studied in the wind wave flow test sin with a long crest wave generator in Tainan Hydraulics Laboratory, National Cheng Kung University. The piezoelectric ocean-wave harvester generated 12.4V (maximum peak voltage) when the frequency and amplitude of incident wave were 1Hz and 100mm, respectively. After rectifying and filtering, 42.05μW was generated by the piezoelectric ocean-wave harvester and 4.14μW was stored in a capacitor.