A Piezoelectric Wave-Energy Converter Equipped with a Geared-Linkage-Based Frequency Up-Conversion Mechanism.

Shao-En Chen,Ray-Yeng Yang,Guang-Kai Wu,Chia-Che Wu

doi:10.3390/s21010204

Abstract

In this paper, a piezoelectric wave-energy converter (PWEC), consisting of a buoy, a frequency up-conversion mechanism, and a piezoelectric power-generator component, is developed. The frequency up-conversion mechanism consists of a gear train and geared-linkage mechanism, which converted lower frequencies of wave motion into higher frequencies of mechanical motion. The slider had a six-period displacement compared to the wave motion and was used to excite the piezoelectric power-generation component. Therefore, the operating frequency of the piezoelectric power-generation component was six times the frequency of the wave motion. The developed, flexible piezoelectric composite films of the generator component were used to generate electrical voltage. The piezoelectric film was composed of a copper/nickel foil as the substrate, lead–zirconium–titanium (PZT) material as the piezoelectric layer, and silver material as an upper-electrode layer. The sol-gel process was used to fabricate the PZT layer. The developed PWEC was tested in the wave flume at the Tainan Hydraulics Laboratory, Taiwan (THL). The maximum height and the minimum period were set to 100 mm and 1 s, respectively. The maximum voltage of the measured value was 2.8 V. The root-mean-square (RMS) voltage was 824 mV, which was measured through connection to an external 495 kΩ resistive load. The average electric power was 1.37 μW.

Highlights

In recent decades, ocean waves have been considered as a potential candidate for renewable energy [1,2]
The wave-activated bodies use a power take-off (PTO) system driven by wave-induced motions of masses or large bodies to generate electricity
We developed a wave-energy convertors (WECs) with a piezoelectric generator

Summary

Introduction

Ocean waves have been considered as a potential candidate for renewable energy [1,2]. Wave energy has gradually attracted more and more attention from researchers [1,2]. According to the European Marine Energy Centre (MEMC), wave-energy convertors (WECs) can be classified into various categories. Three well-known types include wave-activated bodies, oscillating water columns (OWCs), and point absorbers. The wave-activated bodies use a power take-off (PTO) system driven by wave-induced motions of masses or large bodies to generate electricity. Numerous devices have been developed based on this concept; one well-known example is the Pelamis, developed by the Scottish company Pelamis Wave Power (formerly Ocean Power Delivery) in 2004 [3]

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Results

Conclusion