Modelling of Mechanical Nonlinearity in an Electromagnetic Vibration Energy Harvester Using a Forced Duffing Equation

Author(s):  
S. D. Moss ◽  
L. A. Vandewater ◽  
S. C. Galea

This work reports on the modelling and experimental validation of a bi-axial vibration energy harvesting approach that uses a permanent-magnet/ball-bearing arrangement and a wire-coil transducer. The harvester’s behaviour is modelled using a forced Duffing oscillator, and the primary first order steady state resonant solutions are found using the homotopy analysis method (or HAM). Solutions found are shown to compare well with measured bearing displacements and harvested output power, and are used to predict the wideband frequency response of this type of vibration energy harvester. A prototype harvesting arrangement produced a maximum output power of 12.9 mW from a 12 Hz, 500 milli-g (or 4.9 m/s2) rms excitation.

Author(s):  
Hesam Sharghi ◽  
Onur Bilgen

In this paper, vibration energy harvesting from a piezocomposite beam with unconventional boundary conditions is investigated. The beam in consideration has multi-point constraints and consequently has concentrated multi-point loading along its length. It is shown that the natural frequencies, strain uniformity along the beam, and strain node positions can be adjusted by shifting the support locations, allowing for a significant range of mechanical tuning. To model the electromechanical system, the Euler-Bernoulli beam assumptions are adopted, and by Hamilton’s principle and Gauss’ law, the governing equations are derived. Frequency response functions of the output voltage and beam transverse displacement are solved for harmonic base excitation, and the maximum output power is calculated both numerically and analytically. A set of experimental results are used to validate the model. A detailed parametric analysis is conducted by varying tunable system parameters such as resistive load, tip mass, and the intermediate support location. All interesting operational conditions of the system, and the corresponding tuning parameters are quantified. It is shown that the multi-point loaded beam concept can produce higher strain-normalized-output-power when compared to a cantilevered or a simply supported beam.


2013 ◽  
Vol 404 ◽  
pp. 635-639 ◽  
Author(s):  
Xue Feng He ◽  
You Zhu ◽  
Yao Qing Cheng ◽  
Jun Gao

Richness of broadband low-frequency vibration energy in environemnts makes it significant to develop broadband low-frequency vibration energy harvesters. A vibration energy harvester composed of two symmetrical cantilevered piezoelectric bimorphs and a rolling mass in a guiding channel was proposed. A prototype of the vibration energy harvester with a rolling mass was assembled and tested. The base excitation caused the rolling mass to impact with two cantilevered bimorphs repeatedly and the impacts cause the bimorphs to vibrate dramatically. Experimental results show that maximum output power and corresponding excitation frequency increased with the amplitude of base acceleration. For the prototype, the maximum output power of a piezoelectric bimorph on a resistor with the resistance of 100 kΩ was 602 μW under base acceleration with the amplitude of 1.5 g and frequency of 37 Hz, and the half power bandwidth was about 13.5% or 5 Hz.


2019 ◽  
Vol 20 (1) ◽  
pp. 90-99
Author(s):  
Aliza Aini Md Ralib ◽  
Nur Wafa Asyiqin Zulfakher ◽  
Rosminazuin Ab Rahim ◽  
Nor Farahidah Za'bah ◽  
Noor Hazrin Hany Mohamad Hanif

Vibration energy harvesting has been progressively developed in the advancement of technology and widely used by a lot of researchers around the world. There is a very high demand for energy scavenging around the world due to it being cheaper in price, possibly miniaturized within a system, long lasting, and environmentally friendly. The conventional battery is hazardous to the environment and has a shorter operating lifespan. Therefore, ambient vibration energy serves as an alternative that can replace the battery because it can be integrated and compatible to micro-electromechanical systems. This paper presents the design and analysis of a MEMS piezoelectric energy harvester, which is a vibration energy harvesting type. The energy harvester was formed using Lead Zicronate Titanate (PZT-5A) as the piezoelectric thin film, silicon as the substrate layer and structural steel as the electrode layer. The resonance frequency will provide the maximum output power, maximum output voltage and maximum displacement of vibration. The operating mode also plays an important role to generate larger output voltage with less displacement of cantilever. Some designs also have been studied by varying height and length of piezoelectric materials. Hence, this project will demonstrate the simulation of a MEMS piezoelectric device for a low power electronic performance. Simulation results show PZT-5A piezoelectric energy with a length of 31 mm and height of 0.16 mm generates maximum output voltage of 7.435 V and maximum output power of 2.30 mW at the resonance frequency of 40 Hz. ABSTRAK: Penuaian tenaga getaran telah berkembang secara pesat dalam kemajuan teknologi dan telah digunakan secara meluas oleh ramai penyelidik di seluruh dunia. Terdapat permintaan yang sangat tinggi di seluruh dunia terhadap penuaian tenaga kerana harganya yang lebih murah, bersaiz kecil dalam satu sistem, tahan lama dan mesra alam. Manakala, bateri konvensional adalah berbahaya bagi alam sekitar dan mempunyai jangka hayat yang lebih pendek. Oleh itu, getaran tenaga dari persekitaran lebih sesuai sebagai alternatif kepada bateri kerana ia mudah diintegrasikan dan serasi dengan sistem mikroelektromekanikal. Kertas kerja ini  membentangkan reka bentuk dan analisis tenaga piezoelektrik MEMS iaitu salah satu jenis penuaian tenaga getaran. Penuai tenaga ini dibentuk menggunakan Lead Zicronate Titanate (PZT-5A) sebagai lapisan filem tipis piezoelektrik, silikon sebagai lapisan substrat dan keluli struktur sebagai lapisan elektrod. Frekuensi resonans akan memberikan hasil tenaga maksima, voltan tenaga maksima dan getaran jarak maksima. Mod pengendalian juga memainkan peranan penting bagi menghasilkan tenaga yang lebih besar. Reka bentuk yang mempunyai ketinggian dan panjang berlainan juga telah diuji dengan menggunakan bahan piezoelektrik yang sama. Oleh itu, projek ini akan menghasilkan simulasi piezoelektrik MEMS yang sesuai digunakan bagi alat elektronik berkuasa rendah. Hasil simulasi menunjukkan dengan panjang 31 mm dan ketinggian 0.16 mm, piezoelektrik PZT ini menghasilkan voltan maksima sebanyak 7.435 V dan tenaga output maksima 2.30 mW pada frekuensi resonans 40 Hz.


Energies ◽  
2019 ◽  
Vol 12 (14) ◽  
pp. 2710 ◽  
Author(s):  
Zhuang Lu ◽  
Quan Wen ◽  
Xianming He ◽  
Zhiyu Wen

The performance of vibration energy harvesters is usually restricted by their frequency bandwidth. The double-clamped beam with strong natural nonlinearity is a simple way that can effectively expand the frequency bandwidth of the vibration energy harvester. In this article, a nonlinear electromagnetic vibration energy harvester with monostable double-clamped beam was proposed. A systematic analysis was conducted and a distributed parameter analytical model was established. On this basis, the output performance was estimated by the analytical model. It was found that the nonlinearity of the double-clamped beam had little influence on the maximum output, while broadening the frequency bandwidth. In addition, the resonant frequency, the frequency bandwidth, and the maximum output all increased following the increase of excitation level. Furthermore, the resonant frequency varies with the load changes, due to the electromagnetic damping, so the maximum output power should be gained at its optimum load and frequency. To experimentally verify the established analytical model, an electromagnetic vibration energy harvester demonstrator was built. The prediction by the analytical model was confirmed by the experiment. As a result, the open-circuit voltage, the average power and the frequency bandwidth of the electromagnetic vibration energy harvester can reach up to 3.6 V, 1.78 mW, and 11 Hz, respectively, under only 1 G acceleration, which shows a prospect for the application of the electromagnetic vibration energy harvester based on a double-clamped beam.


Energies ◽  
2020 ◽  
Vol 13 (3) ◽  
pp. 627 ◽  
Author(s):  
Seong-yeol Yoo ◽  
Young-Woo Park ◽  
Myounggyu Noh

Electromagnetic energy harvesters have been used to capture low-frequency vibration energy of large machines such as diesel generators. The structure of an electromagnetic energy harvester is either planar or tubular. Past research efforts focus on optimally designing each structure separately. An objective comparison between the two structures is necessary in order to decide which structure is advantageous. When comparing the structures, the design variations such as magnetization patterns and the use of yokes must also be considered. In this study, extensive comparisons are made covering all possible topologies of an electromagnetic energy harvester. A bench mark harvester is defined and the parameters that produce maximum output power are identified for each topology. It is found that the tubular harvesters generally produce larger output power than the planar counterparts. The largest output power is generated by the tubular harvester with a Halbach magnetization pattern (94.7 mW). The second best is the tubular harvester with axial magnetization pattern (79.1 mW) when moving yokes are inserted between permanent magnets for flux concentration. When cost is of primary concern, the tubular harvester with axial pattern may become a best option.


Author(s):  
Yu-ji Gao ◽  
Yong-gang Leng ◽  
Lin-chen Shen ◽  
Yan Guo

A vibration energy harvester is typically composed of a spring–mass system, with the advantage of high energy density, simple structure and easily being miniaturized. Recently, effects of cantilever beam’s structural parameters and cross-section shape on energy-harvesting micro-device is concerned and investigated in this paper, so as to study its performance of energy harvesting to meet the needs of low resonant frequency and maximum output power. The effect of a cantilever beam’s structure dimensions as well as quality of the mass on the device’s resonance frequency and maximum output power can be detected through formula computing. Further study on effect of a cantilever beam’s cross-section shape has also been worked out. According to the simulation experimental results gained from ANSYS with appropriate parameters defined by theoretical derivation, we manage to receive concordant conclusions. To receive a better performance of the energy harvester, we should choose a shorter, wider and thicker cantilever beam with rectangular cross-section and heavier mass at its end. However, to meet the requirement of low resonant frequency for piezoelectric vibration energy harvesting, we still need to define either an upper or a lower limit while choosing parameters of the device.


Author(s):  
Dong-Xing Cao ◽  
Wei Xia ◽  
Xiang-Ying Guo ◽  
Siu-Kai Lai

Piezoelectric-based energy harvesting techniques offer a promising way to transform vibration energy into electric energy. However, many vibration energy harvesters (VEH) can only work under narrow bandwidths and limited high frequencies to restrict their working performance. In this paper, a vibro-impact piezoelectric VEH is proposed, where a partial interlayer-separated piezoelectric beam is designed to improve the voltage output and frequency bandwidth of the VEH. First, the mechanism of the proposed VEH is introduced and the electromechanical model is derived based on the Euler-Bernoulli beam theory and vibro-impact dynamic model. Voltage-frequency responses are then obtained by using an approximate analytical method. In addition, the effect of partial interlayer-separated piezoelectric beams on the energy harvesting performance is investigated numerically. A parametric study is performed to investigate the influence of system parameters on the voltage output in terms of bandwidth and magnitude. Finally, the theoretical solutions are validated by experimental results, the voltage output of the proposed VEH is higher than the non-impact type. The maximum output power of the proposed VEH is about 12 times more than that of the conventional one under a 0.2 g acceleration. Due to the good agreement of the variation trend between the theoretical values and experiment results, the proposed partial interlayer-separated beam VEH can be used for a further optimization of the vibration energy harvester.


Energies ◽  
2021 ◽  
Vol 14 (2) ◽  
pp. 391
Author(s):  
Nan Wu ◽  
Yuncheng He ◽  
Jiyang Fu ◽  
Peng Liao

In this paper a novel hybrid piezoelectric and electromagnetic energy harvester for civil engineering low-frequency sloshing environment is reported. The architecture, fabrication and characterization of the harvester are discussed. The hybrid energy harvester is composed of a permanent magnet, copper coil, and PVDF(polyvinylidene difluoride) piezoelectric film, and the upper U-tube device containing a cylindrical fluid barrier is connected to the foundation support plate by a hinge and spring. The two primary means of energy collection were through the vortex street, which alternately impacted the PVDF piezoelectric film through fluid shedding, and the electromotive force (EMF) induced by changes in the magnetic field position in the conducting coil. Experimentally, the maximum output power of the piezoelectric transformer of the hybrid energy harvester was 2.47 μW (circuit load 270 kΩ; liquid level height 80 mm); and the maximum output power of the electromagnetic generator was 2.72 μW (circuit load 470 kΩ; liquid level height 60 mm). The low-frequency sloshing energy collected by this energy harvester can drive microsensors for civil engineering monitoring.


2016 ◽  
Vol 28 (5) ◽  
pp. 578-594 ◽  
Author(s):  
Sri Vikram Palagummi ◽  
Fuh-Gwo Yuan

This article identifies and studies key parameters that characterize a horizontal diamagnetic levitation mechanism–based low frequency vibration energy harvester with the aim of enhancing performance metrics such as efficiency and volume figure of merit. The horizontal diamagnetic levitation mechanism comprises three permanent magnets and two diamagnetic plates. Two of the magnets, lifting magnets, are placed co-axially at a distance such that each attracts a centrally located magnet, floating magnet, to balance its weight. This floating magnet is flanked closely by two diamagnetic plates which stabilize the levitation in the axial direction. The influence of the geometry of the floating magnet, the lifting magnet, and the diamagnetic plate is parametrically studied to quantify their effects on the size, stability of the levitation mechanism, and the resonant frequency of the floating magnet. For vibration energy harvesting using the horizontal diamagnetic levitation mechanism, a coil geometry and eddy current damping are critically discussed. Based on the analysis, an efficient experimental system is setup which showed a softening frequency response with an average system efficiency of 25.8% and a volume figure of merit of 0.23% when excited at a root mean square acceleration of 0.0546 m/s2 and at a frequency of 1.9 Hz.


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