Investigation of a hybrid piezo-electromagnetic energy harvester

Abstract A hybrid energy harvester combining piezoelectric and electromagnetic transduction mechanisms is designed to scavenge vibration energy. The system comprises of a cantilever beam, a piezoelectric harvester and a magnetic mass hung through a spring at the free end. The beam with piezoelectric harvests electrical energy due to the strain induced in the piezoelectric patch. The hung mass oscillates in and out a solenoid to harvest energy due to electromagnetic induction. The system can generate power from any vertically oscillating vibrating host structure. This paper studies the power harvested from the hybrid harvester under harmonic excitation using experimental and analytical evaluations. Comparisons are made with the standalone piezoelectric and electromagnetic harvester under the same excitation environment. The study shows that the present hybrid harvester can harvest energy at a broad range of frequencies. Furthermore few parametric studies are carried out for understanding the device performance. Finally, the efficiency of the proposed hybrid energy harvester is compared with the existing hybrid energy harvester.

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A monostable hybrid energy harvester for capturing energy from low-frequency excitations

Journal of Intelligent Material Systems and Structures ◽

10.1177/1045389x19873420 ◽

2019 ◽

Vol 30 (18-19) ◽

pp. 2716-2732 ◽

Cited By ~ 2

Author(s):

Kangqi Fan ◽

Jiayu Hao ◽

Qinxue Tan ◽

Meiling Cai

Keyword(s):

Power Unit ◽

Energy Harvester ◽

Low Frequency ◽

Theoretical Models ◽

Harmonic Excitation ◽

Hybrid Energy ◽

Hybrid Energy Harvester ◽

Electromagnetic Power ◽

The Individual ◽

Reliability And Robustness

Efficient energy extraction from ubiquitous low-frequency excitations is still an open problem due to the high challenge in constructing an energy harvester with sufficiently low resonant frequency. To address this problem, this article reports a monostable hybrid energy harvester that consists of a piezoelectric power unit and an electromagnetic power unit. The proposed hybrid energy harvester can capture energy simultaneously from one excitation through the two power units. Theoretical models for the monostable hybrid energy harvester are established, and theoretical results fit well with the experimental measurements. Under a harmonic excitation with amplitude of 0.5 g ( g = 9.8 m/s2), the power output of the monostable hybrid energy harvester is experimentally measured to be 0.39 mW, which is obviously higher than that (piezoelectric unit: 0.25 mW; electromagnetic unit: 0.3 mW) produced by the individual power units when they work separately. More importantly, compared with the linear hybrid energy harvester, the monostable hybrid energy harvester has an operating frequency range that is shifted toward the lower frequency and achieves a slightly enhanced peak power, making the monostable hybrid energy harvester well suited for harnessing low-frequency excitations. In addition, employing two transduction mechanisms to synchronously and parallelly generate electricity from ambient excitations, the monostable hybrid energy harvester may also enjoy improved reliability and robustness.

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Frequency Up-Conversion Hybrid Energy Harvester Combining Piezoelectric and Electromagnetic Transduction Mechanisms

International Journal of Precision Engineering and Manufacturing-Green Technology ◽

10.1007/s40684-021-00321-y ◽

2021 ◽

Author(s):

Soonjae Pyo ◽

Dae-Sung Kwon ◽

Hee-Jin Ko ◽

Youngkee Eun ◽

Jongbaeg Kim

Keyword(s):

Energy Harvester ◽

Hybrid Energy ◽

Hybrid Energy Harvester ◽

Transduction Mechanisms ◽

Electromagnetic Transduction

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Study on the Output Performance of a Nonlinear Hybrid Piezoelectric-Electromagnetic Harvester under Harmonic Excitation

Acoustics ◽

10.3390/acoustics1020021 ◽

2019 ◽

Vol 1 (2) ◽

pp. 382-392 ◽

Cited By ~ 3

Author(s):

Haipeng Liu ◽

Shiqiao Gao ◽

Junru Wu ◽

Ping Li

Keyword(s):

Resonant Frequency ◽

Output Power ◽

Average Output Power ◽

Energy Harvester ◽

Harmonic Excitation ◽

Average Output ◽

Hybrid Energy ◽

Output Performance ◽

Hybrid Energy Harvester ◽

Nonlinear Hybrid

The nonlinear energy harvester has become a hot topic due to its broad bandwidth and lower resonant frequency. Based on the preliminary test and analyses in our previous work, further analyses and tests on the influence of parameters, including the nonlinear magnetic force of the hybrid energy harvesting structure on its output performance under harmonic excitation, are performed in this paper, which will provide powerful support for structural optimization. For designing a nonlinear piezoelectric-electromagnetic hybrid energy harvester, the state equation of electromechanical coupling, the harmonic response and average output power, voltage, and current of a nonlinear hybrid energy harvester under harmonic excitation are derived by the harmonic balance method. The effects of the excitation acceleration and the external load on the output performance of the nonlinear hybrid energy harvester are verified through experimental tests. The results showed that the output power of the nonlinear hybrid energy harvester increases with the increase in the acceleration of harmonic excitation, and the increase is affected by external load. When the piezoelectric-electromagnetic hybrid harvester operates at the optimal load and the resonant frequency, the average output power reaches its maximum value and the increase of the load of the piezoelectric unit makes the resonant frequency of the energy harvesting system increase. Compared with linear harvesting structures, the nonlinear hybrid harvester has better flexibility of environmental adaptability and is more suitable for harvesting energy in low-frequency environments.

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