On electrical optimisation using a Duffing-type vibrational energy harvester

2014 ◽  
Vol 229 (18) ◽  
pp. 3308-3319 ◽  
Author(s):  
Dongxu Su ◽  
Kimihiko Nakano ◽  
Rencheng Zheng ◽  
Matthew P Cartmell
Keyword(s):  
High Speed ◽  
Energy Harvester ◽  
Vibrational Energy ◽  
Electrical Power ◽  
Low Frequency ◽  
Load Resistance ◽  
Ball Screw ◽  
Response Analysis ◽  
Practical Implementation ◽  
Maximum Displacement

There has been much recent interest in the response analysis and optimisation of the linear energy harvester under ambient vibrations. To transfer maximum power to an electrical load in a resonant system, the load resistance should be equal to the sum of the electrical analogue of mechanical damping and internal resistance. However, principally because of the limited bandwidth offered by the linear energy harvester, the potential benefit of nonlinearity has recently been applied to improve the effectiveness of energy harvesting devices. For example, a Duffing-type oscillator can provide a wider bandwidth and greater effectiveness when subject to periodic excitations. The motivating hypothesis has been that the nonlinear Duffing energy harvester can also be optimised to maximise the available electrical power. This paper presents theoretical optimisation and numerical studies under three different conditions with the designed Duffing-type devices. First, the simplest model without any transmission mechanism and optimisation constraints is considered. Second, a device operated under low frequency and large force excitations using a ball screw to convert low-speed linear motion to high-speed rotation is analysed, where the optimum lead and load resistance are derived. Finally, considering the limitation of some dimensions in practical implementation, the constrained optimisation subjected to the maximum displacement of the seismic mass is also shown in this paper.

scholarly journals Ultra-Low Frequency Eccentric Pendulum-Based Electromagnetic Vibrational Energy Harvester

Micromachines ◽  
2020 ◽  
Vol 11 (11) ◽  
pp. 1009
Author(s):  
Mingxue Li ◽  
Huichao Deng ◽  
Yufeng Zhang ◽  
Kexin Li ◽  
Shijie Huang ◽  
...  
Keyword(s):  
Low Power ◽  
Energy Harvester ◽  
Vibrational Energy ◽  
Low Frequency ◽  
Sensor Nodes ◽  
Wireless Sensor ◽  
Center Frequency ◽  
Vibration Energy ◽  
Outer Side ◽  
Working Frequency

With the development of low-power technology in electronic devices, the wireless sensor network shows great potential in applications in health tracing and ocean monitoring. These scenarios usually contain abundant low-frequency vibration energy, which can be collected through appropriate energy conversion architecture; thus, the common issue of limited battery life in wireless sensor devices could be solved. Traditional energy-converting structures such as the cantilever-beam type or spring-mass type have the problem of high working frequency. In this work, an eccentric pendulum-based electromagnetic vibration energy harvester is designed, analyzed, and verified with the finite element analysis method. The pendulum that contains alternative distributed magnets in the outer side works as a rotor and has the advantages of a simple structure and low center frequency. The structure size is well scalable, and the optimal output performance can be obtained by optimizing the coil thickness and width for a given diameter of the energy harvester. The simulation results show that the energy harvester could work in ultra-low frequencies of 0.2–3.0 Hz. A full-scale prototype of the energy harvester is manufactured and tested. The center working frequency is 2.0 Hz with an average output power of 8.37 mW, which has potential for application in driving low-power wireless sensor nodes.

Fundamental Study on Friction-Driven Gyroscopic Power Generator Works Under Arbitrary Vibration

2019 ◽  
Author(s):  
Aya Watanabe ◽  
Ryousuke Yuyama ◽  
Hiroshi Hosaka ◽  
Akira Yamashita
Keyword(s):  
Power Generation ◽  
High Speed ◽  
Electrical Power ◽  
Low Frequency ◽  
Inertial Force ◽  
Fundamental Study ◽  
Power Generator ◽  
Energy Harvesters ◽  
Low Frequency Vibration ◽  
Circular Track

Abstract This paper describes a friction-driven gyro generator that works under arbitrary vibrations and generates more than 1 W of power. Vibrational generators are energy harvesters that convert environmental vibrations into electrical power via the inertial force of pendulums. In conventional generators that use simple vibration, the power is less than 10 mW for a wearable size because vibrations in the natural environment are as low as 1 Hz. Gyroscopic generators increase the inertial force by rotating a pendulum at high speed and creating a gyro effect. In this generator, a palm-size product that generates 0.1 W and weighs 280 g has already been commercialized, but this device operates only under a particular vibration that synchronizes rotor precession and stalls under random vibration. To solve this problem, in this research, two gimbals and a precession spring are introduced to support the rotor. We developed a prototype generator with straight tracks measuring 16 cm × 11 cm × 12 cm with a mass of 980 g. Under a vibration of 4 Hz and ±20 degrees, power generation of 1.6 W was confirmed. Next, a prototype circular track was made. Power generation of 0.2 W with a vibration of 1 Hz and ±90 degrees was confirmed. Finally, a simple formula to estimate the upper limit of the generation power is derived. It is suggested that the circular-type generator is suitable for low-frequency vibration and can generate twice the power of a straight-type generator.

scholarly journals Experimental Study and Parameter Optimization of a Magnetic Coupled Piezoelectric Energy Harvester

2018 ◽  
Vol 8 (12) ◽  
pp. 2609 ◽  
Author(s):  
Xiaobo Rui ◽  
Yibo Li ◽  
Yue Liu ◽  
Xiaolei Zheng ◽  
Zhoumo Zeng
Keyword(s):  
Flux Density ◽  
Parameter Optimization ◽  
Energy Harvester ◽  
Fiber Composite ◽  
Electrical Power ◽  
Low Frequency ◽  
Harmonic Excitation ◽  
Lumped Parameter Model ◽  
Peak Output Power ◽  
Piezoelectric Energy

Piezoelectric energy harvesting is a promising way to develop self-sufficient systems. Structural design and parameter optimization are key issues to improve the performance in applications. This paper presents a magnetic coupled piezoelectric energy harvester to increase the output and bandwidth. A lumped parameter model considering the static position is established and various modes are simulated. This paper focuses on the “Low frequency repulsion mode”, which is more practical. The experiment platform is built with the Macro Fiber Composite (MFC) material, and the results are consistent with the analytical simulation. The optimization process of some key parameters, such as magnets spacing and flux density, is carried out. The results show that there is a corresponding optimal spacing for each flux density, which is positive correlated. With the optimized parameter design, the system achieves peak electrical power of 3.28 mW under the harmonic excitation of 4 m/s2. Compared with the conventional single cantilever harvester, the operated bandwidth is increased by 66.7% and the peak output power is increased by 35.0% in experiment.

Optimizing the Electrical Power in an Energy Harvesting System

2015 ◽  
Vol 25 (12) ◽  
pp. 1550171 ◽  
Author(s):  
Mattia Coccolo ◽  
Grzegorz Litak ◽  
Jesús M. Seoane ◽  
Miguel A. F. Sanjuán
Keyword(s):  
Energy Harvesting ◽  
Kinetic Energy ◽  
High Frequency ◽  
Energy Harvester ◽  
Electrical Power ◽  
Low Frequency ◽  
Electrical Energy ◽  
Resonance Phenomenon ◽  
Vibrational Resonance ◽  
Energy Harvesting System

In this paper, we study the vibrational resonance (VR) phenomenon as a useful mechanism for energy harvesting purposes. A system, driven by a low frequency and a high frequency forcing, can give birth to the vibrational resonance phenomenon, when the two forcing amplitudes resonate and a maximum in amplitude is reached. We apply this idea to a bistable oscillator that can convert environmental kinetic energy into electrical energy, that is, an energy harvester. Normally, the VR phenomenon is studied in terms of the forcing amplitudes or of the frequencies, that are not always easy to adjust and change. Here, we study the VR generated by tuning another parameter that is possible to manipulate when the forcing values depend on the environmental conditions. We have investigated the dependence of the maximum response due to the VR for small and large variations in the forcing amplitudes and frequencies. Besides, we have plotted color coded figures in the space of the two forcing amplitudes, in which it is possible to appreciate different patterns in the electrical power generated by the system. These patterns provide useful information on the forcing amplitudes in order to produce the optimal electrical power.

An Experimental Investigation Into the Performance of a T-Shaped Piezoelectric Flow Energy Harvester

2013 ◽  
Author(s):  
P. B. Jain ◽  
M. R. Cacan ◽  
S. Leadenham ◽  
C. De Marqui ◽  
A. Erturk
Keyword(s):  
Geometric Parameter ◽  
Energy Harvester ◽  
Mechanical Response ◽  
Electrical Power ◽  
Response Spectra ◽  
Load Resistance ◽  
Flow Speed ◽  
Research Field ◽  
Flow Energy ◽  
Piezoelectric Cantilever

The harvesting of flow energy by exploiting aeroelastic and hydroelastic vibrations has received growing attention over the last few years. The goal in this research field is to generate low-power electricity from flow-induced vibrations of scalable structures involving a proper transduction mechanism for wireless applications ranging from manned/unmanned aerial vehicles to civil infrastructure systems located in high wind areas. The fundamental challenge is to enable geometrically small flow energy harvesters while keeping the cut-in speed (lowest flow speed that induces persistent oscillations) low. An effective design with reduced cut-in speed is known to be the T-shaped cantilever arrangement that consists of a horizontal piezoelectric cantilever with a perpendicular vertical beam attachment at the tip. The direction of incoming flow is parallel to the horizontal cantilever and perpendicular to the vertical and symmetric tip attachment. Vortex-induced vibration resulting from flow past the tip attachment is the source of the aeroelastic response. For a given width of the T-shaped harvester with fixed thickness parameters, an important geometric parameter is the length ratio of the tip attachment to the cantilever. In this paper we investigate the effect of this geometric parameter on the piezoaeroelastic response of a T-shaped flow energy harvester. A controlled desktop wind tunnel system is used to characterize the electrical and mechanical response characteristics for broad ranges of flow speed and electrical load resistance using different vertical tip attachment lengths for the same horizontal piezoelectric cantilever. The variations of the electrical power output and cut-in speed with changing head length are reported along with an investigation into the electroaeroelastic frequency response spectra.

Investigations of a Stiffness Tunable Nonlinear Vibrational Energy Harvester

2014 ◽  
Vol 14 (08) ◽  
pp. 1440023 ◽  
Author(s):  
Dongxu Su ◽  
Kimihiko Nakano ◽  
Rencheng Zheng ◽  
Matthew P. Cartmell
Keyword(s):  
Energy Harvesting ◽  
Permanent Magnets ◽  
Energy Harvester ◽  
Vibrational Energy ◽  
Duffing Oscillator ◽  
Experimental Tests ◽  
High Energy ◽  
Practical Implementation ◽  
Energy Harvesting Devices ◽  
Energy Orbit

The recent potential benefit of nonlinearity has been applying in order to improve the effectiveness of energy harvesting devices. For instance, at relatively high excitation levels, both low and high-energy responses can coexist for the same parameter combinations in a hardening type Duffing oscillator, and this provides a wider bandwidth and a higher energy harvesting effectiveness under periodic excitations. However, frequency or amplitude sweeps of the excitation must be used in order to reach a desirable high-energy orbit, and this gives a limitation on practical implementation. This paper presents a stiffness tunable nonlinear vibrational energy harvester which contains a moving magnetic end mass attached to a cantilever beam, whose nonlinearity emerges from the interaction forces with two neighboring permanent magnets facing with opposing poles. The motivating hypothesis has been that the jump from the low-energy orbit to the high-energy orbit can be triggered by tuning the stiffness of the system without changing the frequency or the amplitude of the excitation. Theoretical investigations show a methodology for tuning stiffness, and experimental tests have validated that the proposed method can be used to trigger a jump to the desirable state, and hereby this can broaden the bandwidth of the energy harvester.

scholarly journals Efficient Broadband Vibration Energy Harvesting Using Multiple Piezoelectric Bimorphs

2019 ◽  
Vol 87 (4) ◽  
Author(s):  
Hamed Farokhi ◽  
Alireza Gholipour ◽  
Mergen H. Ghayesh
Keyword(s):  
Energy Harvesting ◽  
Energy Harvester ◽  
Nonlinear Models ◽  
Low Frequency ◽  
Load Resistance ◽  
Numerical Continuation ◽  
Vibration Energy Harvesting ◽  
Optimum Load ◽  
In Series ◽  
Piezoelectric Bimorphs

Abstract This paper presents complete nonlinear electromechanical models for energy harvesting devices consisting of multiple piezoelectric bimorphs (PBs) connected in parallel and series, for the first time. The proposed model is verified against available experimental results for a specific case. The piezoelectric and beam constitutive equations and different circuit equations are utilized to derive the complete nonlinear models for series and parallel connections of the PBs as well as those of piezoelectric layers in each bimorph, i.e., four nonlinear models in total. A multi-modal Galerkin approach is used to discretize these nonlinear electromechanical models. The resultant high-dimensional set of equations is solved utilizing a highly optimized and efficient numerical continuation code. Examining the system behavior shows that the optimum load resistance for an energy harvester array of 4 PBs connected in parallel is almost 4% of that for the case with PBs connected in series. It is shown an energy harvesting array of 8 PBs could reach a bandwidth of 14 Hz in low frequency range, i.e., 20–34 Hz. Compared with an energy harvester with 1 PB, it is shown that the bandwidth can be increased by more than 300% using 4 PBs and by more than 500% using 8 PBs. Additionally, the drawbacks of a multi-PB energy harvesting device are identified and design enhancements are proposed to improve the efficiency of the device.

Parametric analysis of multilayered unimorph piezoelectric vibration energy harvesters

2015 ◽  
Vol 23 (15) ◽  
pp. 2538-2553 ◽  
Author(s):  
Ahmed Jemai ◽  
Fehmi Najar ◽  
Moez Chafra
Keyword(s):  
Energy Harvester ◽  
Electrical Power ◽  
Closed Form Solution ◽  
Beam Theory ◽  
Load Resistance ◽  
Form Solution ◽  
Energy Harvesters ◽  
Piezoelectric Energy ◽  
Piezoelectric Cantilever ◽  
Piezoelectric Layers

The use of a multilayer piezoelectric cantilever beam for vibration-based energy harvesting applications has been investigated as an effective technique to increase the harvested electrical power. It has been shown that the multilayered energy harvester performance is very sensitive to the number of layers and their electrical connection due to impedance variations. The objective of this work is to suggest a comprehensive mathematical model of multilayered unimorph piezoelectric energy harvester allowing analytical solution for the harvested voltage and electrical power. The model is used to deeply investigate the influence of different parameters on the harvested power. A distributed-parameter model of the harvester using the Euler–Bernoulli beam theory and Hamilton's principle is derived. Gauss's law is used to derive the electrical equations for parallel and series connections. A closed-form solution is proposed based on the Galerkin procedure and the obtained results are validated with a finite element 3D model. A parametric study is performed to ascertain the influence of the load resistance, the thickness ratio, the number of piezoelectric layers on the tip displacement and the electrical harvested power. It is shown that this model can be easily used to adjust the geometrical and electrical parameters of the energy harvester in order to improve the system's performances. In addition, it is proven that if one of the system's parameter is not correctly tuned, the harvested power can decrease by several orders of magnitude.

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