scholarly journals Load Resistance Optimization of Bi-Stable Electromagnetic Energy Harvester Based on Harmonic Balance

Sensors ◽  
2021 ◽  
Vol 21 (4) ◽  
pp. 1505
Author(s):  
Sungryong Bae ◽  
Pilkee Kim
Keyword(s):  
External Load ◽  
Harmonic Balance ◽  
Energy Harvester ◽  
Load Resistance ◽  
Electromagnetic Energy ◽  
Analytic Approach ◽  
Accurate Estimation ◽  
Vibration Source ◽  
Optimal Load ◽  
Matching Techniques

In this study, a semi-analytic approach to optimizing the external load resistance of a bi-stable electromagnetic energy harvester is presented based on the harmonic balance method. The harmonic balance analyses for the primary harmonic (period-1T) and two subharmonic (period-3T and 5T) interwell motions of the energy harvester are performed with the Fourier series solutions of the individual motions determined by spectral analyses. For each motion, an optimization problem for maximizing the output power of the energy harvester is formulated based on the harmonic balance solutions and then solved to estimate the optimal external load resistance. The results of a parametric study show that the optimal load resistance significantly depends on the inductive reactance and internal resistance of a solenoid coil––the higher the oscillation frequency of an interwell motion (or the larger the inductance of the coil) is, the larger the optimal load resistance. In particular, when the frequency of the ambient vibration source is relatively high, the non-linear dynamic characteristics of an interwell motion should be considered in the optimization process of the electromagnetic energy harvester. Compared with conventional resistance-matching techniques, the proposed semi-analytic approach could provide a more accurate estimation of the external load resistance.

scholarly journals Load Resistance Optimization of a Broadband Bistable Piezoelectric Energy Harvester for Primary Harmonic and Subharmonic Behaviors

2021 ◽  
Vol 13 (5) ◽  
pp. 2865 ◽  
Author(s):  
Sungryong Bae ◽  
Pilkee Kim
Keyword(s):  
Energy Harvester ◽  
Load Resistance ◽  
Oscillation Period ◽  
Ambient Vibration ◽  
Ambient Vibrations ◽  
Frequency Dependency ◽  
Energy Harvesters ◽  
Piezoelectric Energy ◽  
Optimal Load ◽  
Bistable Energy Harvester

In this study, optimization of the external load resistance of a piezoelectric bistable energy harvester was performed for primary harmonic (period-1T) and subharmonic (period-3T) interwell motions. The analytical expression of the optimal load resistance was derived, based on the spectral analyses of the interwell motions, and evaluated. The analytical results are in excellent agreement with the numerical ones. A parametric study shows that the optimal load resistance depended on the forcing frequency, but not the intensity of the ambient vibration. Additionally, it was found that the optimal resistance for the period-3T interwell motion tended to be approximately three times larger than that for the period-1T interwell motion, which means that the optimal resistance was directly affected by the oscillation frequency (or oscillation period) of the motion rather than the forcing frequency. For broadband energy harvesting applications, the subharmonic interwell motion is also useful, in addition to the primary harmonic interwell motion. In designing such piezoelectric bistable energy harvesters, the frequency dependency of the optimal load resistance should be considered properly depending on ambient vibrations.

SPICE Modeling of Electrostatic Energy Harvester for Optimal Load Resistance Analysis

2015 ◽  
Vol 135 (3) ◽  
pp. 116-117 ◽  
Author(s):  
Keidai Minami ◽  
Takayuki Fujita ◽  
Toshikazu Onishi ◽  
Koji Sonoda ◽  
Naoki Miwatani ◽  
...  
Keyword(s):  
Energy Harvester ◽  
Load Resistance ◽  
Electrostatic Energy ◽  
Resistance Analysis ◽  
Optimal Load

Nonlinear dynamics and parametric study of snap through electromagnetic vibration energy harvester using multi-term harmonic balance method

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Devarajan Kaliyannan
Keyword(s):  
Analytical Method ◽  
Harmonic Balance ◽  
Energy Harvester ◽  
Harmonic Balance Method ◽  
Electromagnetic Energy ◽  
Balance Method ◽  
Vibration Energy ◽  
Vibration Energy Harvester ◽  
System Parameters ◽  
Electromagnetic Vibration

Abstract Vibration energy harvester (VEH) has proven to be a favorable potential technique to supply continuous energy from ambient vibrations and its performance is greatly influenced by the design of potential structures. A snap-through mechanism is used in an electromagnetic energy harvester to improve its effectiveness. It mainly comprises of three springs that are configured so that the potential energy of the system has two stable equilibrium points. In this work, a harmonically base excited snap-through electromagnetic vibration energy harvester is investigated by analytical and semi-analytical method. The approximate analytical outcomes are qualitatively and quantitatively supported by semi-analytical method using multi-term harmonic balance method (MHBM).The bifurcation diagram of response current shows that snap-through electromagnetic vibration energy harvesters exhibits periodic intrawell, interwell and chaotic motion when the system parameters are varied. The influence of system parameters on the response of snap-through electromagnetic vibration energy harvester are examined. Nonlinearity produced by the snap-through oscillator improves energy harvesting so that the snap-through electromagnetic energy harvester can outperform the linear energy harvester in the similar size under harmonic excitation. A fitness function was formulated and optimization of the selected parameters was done using genetic algorithm. The parametric optimization leads to a considerable improvement in the harvested current from the system.

scholarly journals Electromechanical Performance Analysis of the Hybrid Piezoelectric-Electromagnetic Energy Harvester under Rotary Magnetic Plucking Excitation

2021 ◽  
Vol 2021 ◽  
pp. 1-20
Author(s):  
Hongyan Wang ◽  
Jiarui Hu ◽  
Gang Sun ◽  
Liying Zou
Keyword(s):  
Electromechanical Coupling ◽  
Energy Harvester ◽  
Average Power ◽  
Load Resistance ◽  
Electromagnetic Energy ◽  
Lumped Parameter Model ◽  
Model Parameters ◽  
Piezoelectric Energy ◽  
Power Inputs ◽  
Power Outputs

This paper presents an analysis of the hybrid piezoelectric-electromagnetic energy harvester (P-EMEH) driven by contactless rotary magnetic plucking. A lumped-parameter model of the hybrid P-EMEH is developed, and the model parameters are determined from the finite element analysis (FEA) method. A parametric study is conducted to investigate the effects of driving force parameters, load resistance, and electromechanical coupling strengths (EMCSs) on the maximal displacements and velocities, average power inputs and outputs, and energy efficiencies of the system for indicating the performance of the hybrid P-EMEH. The results show that the hybrid P-EMEH can obtain the improved power inputs by reducing the gyration radii of the rotary magnet and shortening the gaps between the two magnets. The structural vibrations can be strongly suppressed owing to the optimal piezoelectric power outputs, which can lead to the occurrence of valleys’ power of the electromagnetic element. At weak coupling, the hybrid P-EMEH can achieve higher power outputs than the single piezoelectric energy harvester (PEH) and the single electromagnetic energy harvester (EMEH). At strong coupling, the use of the PEH is more advantageous for energy harvesting due to wider power bandwidths at high dimensionless frequencies when compared with the hybrid P-EMEH. This work provides a fundamental understanding on the effect of load resistance and EMCSs on the dynamic and electrical characteristics of the magnetically plucked hybrid P-EMEH.

scholarly journals A Multi-Mode Broadband Vibration Energy Harvester Based on MEMS 3D Coils

2021 ◽  
Author(s):  
Hanxiao Wu ◽  
Zhi Tao ◽  
Haiwang Li ◽  
Tiantong Xu ◽  
Wenbin Wang ◽  
...  
Keyword(s):  
Output Power ◽  
Energy Harvester ◽  
Load Resistance ◽  
Vibration Energy ◽  
Vibration Energy Harvester ◽  
Copper Electroplating ◽  
Optimal Load ◽  
Power Frequency ◽  
Half Power ◽  
Multi Mode

This paper presents an electromagnetic vibration energy harvester utilizing 3D MEMS coils and multi-mode structure to improve the output power and broaden the frequency band. We fabricated and assembled the prototype, with a pair of 3D coils fabricated by lithography, silicon etching, silicon direct bonding and copper electroplating, et al., which are compatible with CMOS processes. The numerical simulation was conducted to analysis the vibration modes of the spring-mass system, which revealed the multi-mode mechanism of serpentine springs. We also tested the output power-frequency curves for different load and excitation acceleration to investigate the optimal load resistance and the influence of excitation. The test results showed that the proposed prototype can generate 1.2μW power under 992Hz for 1g acceleration with a half-power bandwidth of 65Hz, which are higher than some recent published data, proving the superiority of proposed structure.

scholarly journals Nonlinear Dynamics and Power Generation on a New Bistable Piezoelectric-Electromagnetic Energy Harvester

Complexity ◽  
2020 ◽  
Vol 2020 ◽  
pp. 1-29
Author(s):  
Minghui Yao ◽  
Pengfei Liu ◽  
Hongbo Wang
Keyword(s):  
Power Generation ◽  
Cantilever Beam ◽  
Energy Harvester ◽  
Electromagnetic Energy ◽  
Generation Efficiency ◽  
Dynamic Behaviors ◽  
Optimal Load ◽  
Piezoelectric Cantilever ◽  
Generation Structure ◽  
Electromagnetic Harvester

This paper focuses power generation and nonlinear dynamic behaviors on a new bistable piezoelectric-electromagnetic energy harvester. Three different kinds of piezoelectric cantilever beam structures, which include the monostable piezoelectric cantilever beam, the bistable piezoelectric cantilever beam with spring and magnet, and the bistable piezoelectric cantilever beam with spring, magnet, and coil, are designed. The power generation efficiency and dynamic behaviors for each structure are experimentally studied, respectively. Due to the spring introduced, the system easily goes through the potential barrier. Experimental results show that the power generation structure of the bistable piezoelectric-electromagnetic harvester can vibrate between two steady states in a wider range of the frequency. Therefore, the effective frequency bandwidth is broadened about 2 Hz when the spring is introduced under the condition of the suitable magnetic distance. Comparing with the power generation efficiency for three different kinds of structures, it is found that the bistable piezoelectric-electromagnetic harvester has the optimum characteristics, which include the optimal magnetic distance of 15 mm, the optimal load of 8 MΩ, and the parameters variation law of coils. For this structure, the influences of the external excitation and the magnetic distance on the output voltage and dynamic behaviors of the system are examined.

scholarly journals Load Resistance Optimization of a Magnetically Coupled Two-Degree-of-Freedom Bistable Energy Harvester Considering Third-Harmonic Distortion in Forced Oscillation

Sensors ◽  
2021 ◽  
Vol 21 (8) ◽  
pp. 2668
Author(s):  
Jinhong Noh ◽  
Pilkee Kim ◽  
Yong-Jin Yoon
Keyword(s):  
External Load ◽  
Energy Harvester ◽  
Impedance Matching ◽  
Harmonic Distortion ◽  
Load Resistance ◽  
Third Harmonic ◽  
The Third ◽  
Power Outputs ◽  
Two Degree Of Freedom ◽  
Bistable Energy Harvester

In this study, the external load resistance of a magnetically coupled two-degree-of-freedom bistable energy harvester (2-DOF MCBEH) was optimized to maximize the harvested power output, considering the third-harmonic distortion in forced response. First, the nonlinear dynamic analysis was performed to investigate the characteristics of the large-amplitude interwell motions of the 2-DOF MCBEH. From the analysis results, it was found that the third-harmonic distortion occurs in the interwell motion of the 2-DOF MCBEH system due to the nonlinear magnetic coupling between the beams. Thus, in this study, the third-harmonic distortion was considered in the optimization process of the external load resistance of the 2-DOF MCBEH, which is different from the process of conventional impedance matching techniques suitable for linear systems. The optimal load resistances were estimated for harmonic and swept-sine excitations by using the proposed method, and all the results of the power outputs were in excellent agreements with the numerically optimized results. Furthermore, the associated power outputs were compared with the power outputs obtained by using the conventional impedance matching technique. The results of the power outputs are discussed in terms of the improvement in energy harvesting performance.

Scavenging vibrational energy with a novel bistable electromagnetic energy harvester

2020 ◽  
Vol 29 (2) ◽  
pp. 025022 ◽  
Author(s):  
Bo Yan ◽  
Ning Yu ◽  
Lu Zhang ◽  
Hongye Ma ◽  
Chuanyu Wu ◽  
...  
Keyword(s):  
Energy Harvester ◽  
Vibrational Energy ◽  
Electromagnetic Energy
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