Piezoelectric materials have a unique characterization which can absorb energy from the environment and convert it to electrical energy. In this conducted research energy harvesting of the THin layer UNimorph DrivER (THUNDER) were investigated. THUNDER is a curved PZT which bring considerable benefits in compare of flat PZT such as better vibration absorption capacity and higher energy recovery efficiency. Also one of the most important characteristics of THUNDER is its low resonance frequency. Because the maximum power a harvester can achieve is at its resonance frequency. So it has application in low resonance frequency situations. In this work, general constitutive law for piezoelectric materials is reduced because it is assumed THUNDER is thin and modeled as a Euler-Bernoulli beam. To obtain mechanical-electrical coupling equations, Hamilton principle is used. Hamilton principle is using kinetic and potential energy and work due to the external force as its input. As a result, modals and natural frequency of THUNDER are obtained. Then based on boundary condition, natural frequency can be achieved. By using Rayleigh-Ritz approach and in-extensional assumption and assuming excitation is sinusoidal, discretize mechanical-electrical coupling equations can be written. For the experiment part, two modes energy harvesting circuit is used, the first one is full bridge rectifier in low-level excitation and steps down converter in high-level excitation. Also, resistor and battery are used as an external load. Because rectified voltage is equal battery voltage, so the model needs to be adjusted by putting a step-down converter in the circuit to adjust Voltage and get the maximum power from the model. In the case of the resistor as an external load, the maximum power will achieve near resonance frequency and also by increasing the amplitude of resistors, more power can be achieved by the circuit. Also, step down converter is used in two modes, continuous conduction mode(CCM) and Discontinuous conduction mode(DCM). Power harvesting in this two mode also compared.
|Commitee:||Gu, Keqin, Kweon, Soondo|
|School:||Southern Illinois University at Edwardsville|
|Department:||Mechanical and Industrial Engineering|
|School Location:||United States -- Illinois|
|Source:||MAI 56/03M(E), Masters Abstracts International|
|Keywords:||Energy harvesting, Piezoelectric, THUNDER|
Copyright in each Dissertation and Thesis is retained by the author. All Rights Reserved
The supplemental file or files you are about to download were provided to ProQuest by the author as part of a
dissertation or thesis. The supplemental files are provided "AS IS" without warranty. ProQuest is not responsible for the
content, format or impact on the supplemental file(s) on our system. in some cases, the file type may be unknown or
may be a .exe file. We recommend caution as you open such files.
Copyright of the original materials contained in the supplemental file is retained by the author and your access to the
supplemental files is subject to the ProQuest Terms and Conditions of use.
Depending on the size of the file(s) you are downloading, the system may take some time to download them. Please be