scholarly journals A Three-Axial Frequency-Tunable Piezoelectric Energy Harvester Using a Magnetic-Force Configuration

2014 ◽  
Vol 14 (9) ◽  
pp. 3152-3163 ◽  
Author(s):  
Tien-Kan Chung ◽  
Chieh-Min Wang ◽  
Po-Chen Yeh ◽  
Tzu-Wei Liu ◽  
Chia-Yuan Tseng ◽  
...  
Keyword(s):  
Magnetic Force ◽  
Energy Harvester ◽  
Piezoelectric Energy ◽  
Frequency Tunable ◽  
Axial Frequency

Experimental Study of Resonant Frequency Tunable Piezoelectric Energy Harvester

2013 ◽  
Vol 345 ◽  
pp. 463-466
Author(s):  
Xiao Yi Zhang ◽  
Jun Wu Kan ◽  
Dian Long Liu ◽  
Shu Yun Wang
Keyword(s):  
Resonant Frequency ◽  
Magnetic Force ◽  
Energy Harvester ◽  
Vibrational Energy ◽  
Great Influence ◽  
Repulsive Force ◽  
Magnetic Dipoles ◽  
Piezoelectric Energy ◽  
Frequency Tunable ◽  
Magnetic Poles

Abstract. To improve energy harvesting performance, a resonance frequency tunable piezoelectric (PZT) energy harvester for vibrating applications was presented and investigated experimentally. A piezoelectric vibrational energy harvester (PVEH) consisted of a piezo-cantilever with a permanent magnet at its free-end and another excitation magnet fixed on vibration structure. The two magnets are placed with the same magnetic poles facing each other to produce repulsive force. The cantilever has dimensions of 70x10x0.6mm3, clamped 10mm, and two magnets sized ø10x4mm3. The testing results show that the magnetic force, denoted by the initial separated distance between the magnetic dipoles (SDMD), exerts great influence on the generated performance. With the SDMD increasing from 15mm to 40mm, the generated voltage rises from 24.4V to 40V, and the resonant frequency increases from 33.75Hz to 38.75Hz.

Dynamics of Vibration Energy Harvester Governed by Gravity and Magnetic Force in a Rotating Wind Turbine Blade

2018 ◽  
Author(s):  
Saman Nezami ◽  
HyunJun Jung ◽  
Myung Kyun Sung ◽  
Soobum Lee
Keyword(s):  
Angular Velocity ◽  
Wind Turbine ◽  
Magnetic Force ◽  
Energy Harvester ◽  
Turbine Blades ◽  
Wind Turbine Blades ◽  
Vibration Energy Harvester ◽  
Coupled Equations ◽  
Piezoelectric Energy ◽  
Gravity And Magnetic

This paper presents mathematical modeling of an energy harvester (EH) for a wireless structure health monitoring (SHM) system in wind turbine blades. The harvester consists of a piezoelectric energy harvester (PEH) beam, a gravity-induced disk, and magnets attached to both the beam and the disk. An electromechanical model of the proposed EH is developed using the energy method with repelling magnetic force considered. The three coupled equations — the motion of the disk, the vibration of the beam, and the voltage output — are derived and solved using ODE45 in MATLAB software. The result showed the blade rotation speed affects the output angular velocity of disk and the output PEH voltage. That is, as the blade speed increases, the disk angular velocity becomes nonlinear and chaotic which is more beneficial to generate larger power.

Nonlinear magnetic force and dynamic characteristics of a tri-stable piezoelectric energy harvester

2019 ◽  
Vol 97 (4) ◽  
pp. 2371-2397 ◽  
Author(s):  
Guangqing Wang ◽  
Wei-Hsin Liao ◽  
Zexiang Zhao ◽  
Jiangping Tan ◽  
Sujuan Cui ◽  
...  
Keyword(s):  
Dynamic Characteristics ◽  
Magnetic Force ◽  
Energy Harvester ◽  
Piezoelectric Energy

Nonlinear Characteristics for Rotatable Magnetically Coupling Piezoelectric Energy Harvesters

2014 ◽  
Author(s):  
Junyi Cao ◽  
Shengxi Zhou ◽  
Daniel J. Inman
Keyword(s):  
Inclination Angle ◽  
Nonlinear Dynamic ◽  
Magnetic Force ◽  
Energy Harvester ◽  
Low Frequency ◽  
High Energy ◽  
Nonlinear Characteristics ◽  
Energy Harvesters ◽  
Piezoelectric Energy ◽  
Frequency Excitation

This paper investigates the nonlinear dynamic characteristics of a magnetically coupled piezoelectric energy harvesters under low frequency excitation, where the angle of external magnetic field is adjustable. The nonlinear dynamic equation with the identified nonlinear magnetic force is derived to describe the electromechanical interaction of variable inclination angle harvesters. The effect of excitation amplitude and frequency on dynamic behavior is proposed by using the phase trajectory and bifurcation diagram. The numerical analysis shows that a rotatable magnetically coupling energy harvesting system exhibits rich nonlinear characteristics with the change of external magnet inclination angle. The nonlinear route to and from large amplitude high energy motion can be clearly observed. It is demonstrated numerically and experimentally that lumped parameters equations with an identified polynomials for magnetic force could adequately describe the characteristics of nonlinear energy harvester. The rotating magnetically coupled energy harvester possesses the usable frequency bandwidth over a wide range of low frequency excitation by adjusting the angular orientation.

Nonlinear Dynamics of a Special Piezoelectric Energy Harvester With a Special Bistable Piezoelectric Cantilever Beam

2018 ◽  
Author(s):  
Ming Hui Yao ◽  
Wei Xia ◽  
Wei Zhang ◽  
Jian Yu Jiao
Keyword(s):  
Permanent Magnet ◽  
Cantilever Beam ◽  
Piezoelectric Layer ◽  
Magnetic Force ◽  
Energy Harvester ◽  
Excitation Frequency ◽  
High Energy ◽  
Nonlinear Phenomenon ◽  
Piezoelectric Energy ◽  
Piezoelectric Cantilever

This paper presents a special piezoelectric energy harvester system which is obtained by separating the end of the upper piezoelectric layer of the traditional piezoelectric cantilever beam from its basic layer. A mass I is located at the end of the separated upper piezoelectric layer (SUPL), a mass II and a permanent magnet I are located at the end of the separated lower piezoelectric beam (SLPB) and a permanent magnet II is added in the opposite position of the permanent magnet I and they face each other with same polarities. A nonlinear magnetic force which can broaden the frequency bandwidth of the system is generated mutually on the two permanent magnets. Studies find that this special piezoelectric energy harvester has extremely high energy capture efficiency. In order to further explore the reason of high efficiency, experimental research on its dynamic behavior is carried out. The experimental results show that the vibrations of the SUPL and the SLPB are relatively simple. The dynamic behaviors of the SUPL, the SLPB and the unseparated part are different. The unseparated part of the piezoelectric shows relatively complex nonlinear phenomenon due to the interaction of nonlinear magnetic force and the collision. With the increase of the external excitation frequency, period doubling motion and almost periodic motion appear alternately.

scholarly journals Development of a Non-Linear Bi-Directional Vortex-Induced Piezoelectric Energy Harvester with Magnetic Interaction

Sensors ◽  
2021 ◽  
Vol 21 (7) ◽  
pp. 2299
Author(s):  
Wei-Jiun Su ◽  
Zong-Siang Wang
Keyword(s):  
Magnetic Force ◽  
Energy Harvester ◽  
Beam Theory ◽  
Magnetic Interaction ◽  
Peak Voltage ◽  
Piezoelectric Energy ◽  
Vortex Induced Vibrations ◽  
Charge Model ◽  
Non Linear ◽  
Lock In

In this study, magnetic force is introduced to the design of a bi-directional U-shaped piezoelectric energy harvester for vortex-induced vibrations. The theoretical model of the beam structure is derived based on the Euler–Bernoulli beam theory. The vortex-induced vibration and the non-linear magnetic force are modeled according to the Rayleigh oscillator and the charge model, respectively. A prototype is fabricated and tested in two orthogonal directions under vortex-induced vibrations in a wind tunnel. Up and down wind-speed sweeps are carried out to investigate the non-linear responses of the harvester. The distance between the magnets and the length of the side beams are adjusted to examine the influence of the magnetic force on the lock-in region and voltage output of the harvester. Overall, the harvester shows strong non-linearity in the horizontal excitations. After adding magnets to the system, significant improvement of the lock-in region and the peak voltage is noticed in the horizontal mode under both up and down sweeps.

A modified magnetic force model and experimental validation of a tri-stable piezoelectric energy harvester

2020 ◽  
Vol 31 (7) ◽  
pp. 967-979 ◽  
Author(s):  
Guangqing Wang ◽  
Haiqiang Wu ◽  
Wei-Hsin Liao ◽  
Sujuan Cui ◽  
Zexiang Zhao ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Magnetic Separation ◽  
Magnetic Dipole ◽  
Magnetic Force ◽  
Energy Harvester ◽  
Separation Distance ◽  
Force Model ◽  
Point Dipole ◽  
Transition Mechanism ◽  
Piezoelectric Energy

Nonlinear tri-stable piezoelectric energy harvesters with magnetic field coupling have attracted many researchers’ interest in ambient vibration energy harvesting and conversion. In such a tri-stable piezoelectric energy harvester, the nonlinear magnetic force generated by the external magnetic field is mainly calculated by the equivalent magnetic dipole method. However, this method will give highly erroneous results when the magnetic separation distance is small. This study presents a modified magnetic force model to precisely calculate the nonlinear magnetic force exerted on the tip of the cantilever beam. Unlike the equivalent magnetic dipole method regarding the magnet as a point dipole at its body center, this model only considers the surface magnetization current of the left and right surfaces of the magnets and replaced them by the one of the center point dipoles on these associated surfaces. With this model, the nonlinear magnetic force, the potential energy, and the transition mechanism of the tri-stable piezoelectric energy harvester are numerically investigated. Experimental validations are consequently performed to testify the numerical results. Compared with the equivalent magnetic dipole method, the modified magnetic force model has a much higher accuracy to be more applicable for different magnetic separation distances, especially when the magnetic separation distance is small.

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