Scavenging power from ultra-low frequency and large amplitude vibration source through a new non-resonant electromagnetic energy harvester

2020 ◽  
Vol 222 ◽  
pp. 113233
Author(s):  
Yecheng Shen ◽  
Kaiyuan Lu
Keyword(s):  
Large Amplitude ◽  
Energy Harvester ◽  
Low Frequency ◽  
Electromagnetic Energy ◽  
Vibration Source ◽  
Amplitude Vibration ◽  
Large Amplitude Vibration

Micro Electromagnetic Vibration Energy Harvester Based on Combined Free/Impact Motion for Low Frequency-Large Amplitude Operation

2017 ◽  
Author(s):  
Ahmed Haroun ◽  
Ichiro Yamada ◽  
Shinichi Warisawa
Keyword(s):  
Large Amplitude ◽  
Energy Harvester ◽  
Low Frequency ◽  
Vibration Energy ◽  
Vibration Source ◽  
Total Size ◽  
Vibration Energy Harvester ◽  
Significant Power ◽  
Electromagnetic Vibration ◽  
Impact Motion

This paper presents design, simulation, and experimentation of a novel Micro-electromagnetic vibration energy harvester based on free/impact motion. Power harvesting is simply achieved from relative oscillation between a permanent magnet allowed to move freely inside a tube-carrying electrical coil with two end stoppers and directly connected to the vibration source. The proposed harvester with free/impact motion shows a non-resonant behaviour in which the output power continuously increase with the input frequency and/or amplitude. In addition, the allowable free motion permits significant power scavenging at low frequencies. Hence, the proposed harvester is well suited for the applications involved variable large amplitude–low frequency vibrations such as human-powered devices. A nonlinear mathematical model of the proposed harvester including electromagnetic and impact characteristics is derived and used further for a case study model prediction. A unique way of oscillation is observed, in which four modes of magnet/tube relative motion appear over the range of exciting amplitudes and frequencies. Two experiments are conducted on different fabricated prototypes. The first shows the effect of different magnet shapes on the harvesting performance, and the second is carried out to investigate the performance of two different size prototypes with variable large amplitude-low frequency vibrations. A harvester with cylindrical total size of D9×L12 mm can generate RMS power of 71.8μW at (2.5 Hz and 5.2 m/s2), and 113.3μW at (3.33 Hz, and 12.38 m/s2). Another of D7×L12 mm size can generate RMS power of 28.4 μW at (2.5 Hz and 5.2 m/s2), and 82.9 μW at (3.33 Hz, and 12.38 m/s2). Comparison with some previously fabricated low frequency energy harvesters is made which shows the advantageous of the new harvester in size minimization as well as the significant power raise with the input amplitude.

Semi-active vibration control of a rotating flexible plate using stiffness and damping actively tunable joint

2019 ◽  
Vol 25 (21-22) ◽  
pp. 2819-2833 ◽  
Author(s):  
Wei Hu ◽  
Yulong Gao ◽  
Xiaoqing Sun ◽  
Yikun Yang ◽  
Bintang Yang
Keyword(s):  
Large Amplitude ◽  
Low Frequency ◽  
Variable Stiffness ◽  
Experimental Results ◽  
Flexible Plate ◽  
Frequency Range ◽  
Amplitude Vibration ◽  
Variable Damping ◽  
Large Amplitude Vibration ◽  
Stiffness And Damping

Lighter structures are increasingly required for flexible spacecraft. However, low frequency and large amplitude vibration problems are unavoidable due to external disturbances or attitude maneuvering especially when working under a microgravity environment. Therefore, a new methodology involving a semi-active technique using an actively tunable joint with variable stiffness and damping control, capable of handling such issues is proposed in this study. The incentive active joint was conceived with a compact structure, based on the electromagnetic direct drive principle. First, a dynamic model of rotating flexible plate was established. Then, a prototype was fabricated and tested. Finally, on the one hand, numerical simulations and experimental results indicated that, when the joint torsional stiffness changed, a frequency shift phenomenon occurred. On the other hand, two types of noncontact periodic vibration excitation methods along the rotation direction were proposed and the experimental results validated that the major frequency bandwidth of interference signal was 0.08–0.52 Hz with a significant vibration attenuation of 5.5–31.5 dB in effective bandwidth. Moreover, in the low frequency range (0.08–0.43 Hz), variable damping was found to be the main factor and variable stiffness was the secondary factor. However, in the high frequency range (around 0.52 Hz), variable stiffness was dominant and variable damping was inferior. These findings are expected to effectively suppress the low frequency and large amplitude vibration of solar panels with flexible joints.

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 Study of the Properties of a Hybrid Piezoelectric and Electromagnetic Energy Harvester for a Civil Engineering Low-Frequency Sloshing Environment

Energies ◽  
2021 ◽  
Vol 14 (2) ◽  
pp. 391
Author(s):  
Nan Wu ◽  
Yuncheng He ◽  
Jiyang Fu ◽  
Peng Liao
Keyword(s):  
Output Power ◽  
Energy Harvester ◽  
Civil Engineering ◽  
Maximum Output Power ◽  
Low Frequency ◽  
Electromagnetic Energy ◽  
Maximum Output ◽  
Piezoelectric Film ◽  
Hybrid Energy ◽  
Level Height

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.

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