scholarly journals Design Optimization and Comparison of Cylindrical Electromagnetic Vibration Energy Harvesters

Sensors ◽  
2021 ◽  
Vol 21 (23) ◽  
pp. 7985
Author(s):  
Tra Nguyen Phan ◽  
Jesus Javier Aranda ◽  
Bengt Oelmann ◽  
Sebastian Bader
Keyword(s):  
Power Density ◽  
Output Power ◽  
Electromagnetic Coupling ◽  
Maximum Output Power ◽  
Optimization Procedure ◽  
Vibration Energy ◽  
Maximum Output ◽  
Energy Harvesters ◽  
Electromagnetic Vibration ◽  
Halbach Array

Investigating the coil–magnet structure plays a significant role in the design process of the electromagnetic energy harvester due to the effect on the harvester’s performance. In this paper, the performance of four different electromagnetic vibration energy harvesters with cylindrical shapes constrained in the same volume were under investigation. The utilized structures are (i) two opposite polarized magnets spaced by a mild steel; (ii) a Halbach array with three magnets and one coil; (iii) a Halbach array with five magnets and one coil; and (iv) a Halbach array with five magnets and three coils. We utilized a completely automatic optimization procedure with the help of an optimization algorithm implemented in Python, supported by simulations in ANSYS Maxwell and MATLAB Simulink to obtain the maximum output power for each configuration. The simulation results show that the Halbach array with three magnets and one coil is the best for configurations with the Halbach array. Additionally, among all configurations, the harvester with two opposing magnets provides the highest output power and volume power density, while the Halbach array with three magnets and one coil provides the highest mass power density. The paper also demonstrates limitations of using the electromagnetic coupling coefficient as a metric for harvester optimization, if the ultimate goal is maximization of output power.

scholarly journals Topology Selection and Parametric Design of Electromagnetic Vibration Energy Harvesters by Combining FEA-in-the-Loop and Analytical Approaches

Energies ◽  
2020 ◽  
Vol 13 (3) ◽  
pp. 627 ◽  
Author(s):  
Seong-yeol Yoo ◽  
Young-Woo Park ◽  
Myounggyu Noh
Keyword(s):  
Output Power ◽  
Permanent Magnets ◽  
Energy Harvester ◽  
Maximum Output Power ◽  
Electromagnetic Energy ◽  
Vibration Energy ◽  
Maximum Output ◽  
Primary Concern ◽  
Energy Harvesters ◽  
Analytical Approaches

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.

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

2012 ◽  
Author(s):  
S. D. Moss ◽  
L. A. Vandewater ◽  
S. C. Galea
Keyword(s):  
Output Power ◽  
Energy Harvester ◽  
Duffing Oscillator ◽  
Maximum Output Power ◽  
Vibration Energy ◽  
Maximum Output ◽  
Vibration Energy Harvesting ◽  
Vibration Energy Harvester ◽  
Homotopy Analysis ◽  
Wire Coil

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.

scholarly journals Finite Time Thermodynamic Optimization of an Irreversible Proton Exchange Membrane Fuel Cell for Vehicle Use

Processes ◽  
2019 ◽  
Vol 7 (7) ◽  
pp. 419 ◽  
Author(s):  
Changjie Li ◽  
Ye Liu ◽  
Bing Xu ◽  
Zheshu Ma
Keyword(s):  
Power Density ◽  
Output Power ◽  
Proton Exchange Membrane ◽  
Operating Temperature ◽  
Maximum Output Power ◽  
Proton Exchange ◽  
Maximum Output ◽  
Operating Pressure ◽  
Output Efficiency ◽  
Exchange Membrane

A finite time thermodynamic model of an irreversible proton exchange membrane fuel cell (PEMFC) for vehicle use was established considering the effects of polarization losses and leakage current. Effects of operating parameters, including operating temperature, operating pressure, proton exchange membrane water content, and proton exchange membrane thickness, on the optimal performance of the irreversible PEMFC are numerically studied in detail. When the operating temperature of the PEMFC increases, the optimal performances of PEMFC including output power density, output efficiency, ecological objective function, and ecological coefficient of performance, will be improved. Among them, the optimal ecological objective function increased by 81%. The proton film thickness has little effect on the output efficiency and the ecological of coefficient performance. The maximum output power density increased by 58% as the water content of the proton exchange membrane increased from 50% to the saturation point. The maximum output power density increases with the operating pressure.

4H-SiC Planar MESFETs on High-Purity Semi-Insulating Substrates

2007 ◽  
Vol 556-557 ◽  
pp. 763-766 ◽  
Author(s):  
Jeong Hyuk Yim ◽  
Ho Keun Song ◽  
Jeong Hyun Moon ◽  
Han Seok Seo ◽  
Jong Ho Lee ◽  
...  
Keyword(s):  
Power Density ◽  
Output Power ◽  
High Purity ◽  
Maximum Output Power ◽  
Drain Current ◽  
Maximum Output ◽  
Power Gain ◽  
Si Substrates ◽  
Class A ◽  
Current Instability

Planar MESFETs were fabricated on high-purity semi-insulating (HPSI) 4H-SiC substrates. The saturation drain current of the fabricated MESFETs with a gate length of 0.5 μm and a gate width of 100 μm was 430 mA/mm, and the transconductance was 25 mS/mm. The maximum oscillation frequency and cut-off frequency were 26.4 GHz and 7.2 GHz, respectively. The power gain was 8.4 dB and the maximum output power density was 2.8 W/mm for operation of class A at CW 2 GHz. MESFETs on HPSI substrates showed no current instability and much higher output power density in comparison to MESFETs on vanadium-doped SI substrates.

Comparison of Piezoelectric Materials for Vibration Energy Conversion Devices

2006 ◽  
Vol 966 ◽  
Author(s):  
Dongna Shen ◽  
Song-Yul Choe ◽  
Dong-Joo Kim
Keyword(s):  
Energy Conversion ◽  
Power Density ◽  
Polyvinylidene Fluoride ◽  
Piezoelectric Materials ◽  
Fiber Composite ◽  
Maximum Output Power ◽  
Vibration Energy ◽  
Maximum Output ◽  
Mems Devices ◽  
Power Requirement

ABSTRACTPiezoelectric materials have been investigated as vibration energy converters to power wireless devices or MEMS devices due to recent low power requirement of such devices and the development of miniaturization technology. It has shown the potential that piezoelectric power generator can be an alternative to the traditional power source-battery because of facile vibration sources in our environment and the potential elimination of maintenance required for large volume batteries. To date, PZT (Lead Zirconium Titanate) has been commonly exploited as a piezoelectric material for energy conversion since it can generate higher power density even at low-g (< 1 g) vibration environment. Its high fragility, however, can limit its applicability at high-g conditions. Therefore, other types of piezoelectric materials such as polymer and composite are necessary to investigate the applicability at severe vibration conditions. In this study, piezoelectric power generators based on cantilever beam structure were designed, optimized, and fabricated by considering matching the resonant frequency with environmental vibration, achieving maximum output power, and reaching maximum g-value without device failure. As piezoelectric materials, ceramic PZT, polymer PVDF (Polyvinylidene fluoride) and composite MFC (Macro Fiber Composite) were utilized. The energy conversion of all three types of generator devices was systematically evaluated. All three devices were measured to generate enough power density for providing electric energy to wireless sensor or MEMS device. The PZT device shows the highest output energy density and PVDF device has the highest durability to operate at high-g vibration condition.

Influence of electrical impedance and mechanical bistability on Galfenol-based unimorph harvesters

2016 ◽  
Vol 28 (3) ◽  
pp. 421-431 ◽  
Author(s):  
Zhangxian Deng ◽  
Marcelo J Dapino
Keyword(s):  
Power Density ◽  
Output Power ◽  
Maximum Output Power ◽  
Element Model ◽  
Maximum Energy ◽  
Bistable System ◽  
Maximum Output ◽  
Base Excitation ◽  
Frequency Bandwidth ◽  
Electrical Loads

A study on iron-gallium (Galfenol) unimorph harvesters is presented which is focused on extending the power density and frequency bandwidth of these devices. A thickness ratio of 2 (ratio of substrate to Galfenol thickness) has been shown to achieve maximum power density under base excitation, but the effect of electrical load capacitance on performance has not been investigated. This article experimentally analyzes the influence of capacitive electrical loads and extends the excitation type to tip impulse. For resistive-capacitive electrical loads, the maximum energy conversion efficiency achieved under impulsive excitation is 5.93%, while the maximum output power and output power density observed for a 139.5 Hz, 3 [Formula: see text] amplitude sinusoidal base excitation is 0.45 W and 6.88 [Formula: see text], respectively, which are 8% higher than those measured under purely resistive loads. A finite element model for Galfenol unimorph harvesters, which incorporates magnetic, mechanical, and electrical dynamics, is developed and validated using impulsive responses. A buckled unimorph beam is experimentally investigated. The proposed bistable system is shown to extend the harvester’s frequency bandwidth.

scholarly journals A Nonlinear Broadband Electromagnetic Vibration Energy Harvester Based on Double-Clamped Beam

Energies ◽  
2019 ◽  
Vol 12 (14) ◽  
pp. 2710 ◽  
Author(s):  
Zhuang Lu ◽  
Quan Wen ◽  
Xianming He ◽  
Zhiyu Wen
Keyword(s):  
Resonant Frequency ◽  
Analytical Model ◽  
Energy Harvester ◽  
Maximum Output Power ◽  
Average Power ◽  
Vibration Energy ◽  
Maximum Output ◽  
Frequency Bandwidth ◽  
Vibration Energy Harvester ◽  
Electromagnetic Vibration

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.

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