scholarly journals On the Effect of the Electrical Load On Vibration Energy Harvesting Under Stochastic Resonance

2020 ◽  
Author(s):  
Panagiotis Alevras
Keyword(s):  
Energy Harvesting ◽  
Stochastic Resonance ◽  
Power Output ◽  
Broadband Noise ◽  
Nonlinear Dependence ◽  
Vibration Energy ◽  
Optimal Harvesting ◽  
Vibration Energy Harvesting ◽  
Promising Alternative ◽  
Energy Harvesters

Abstract Vibration energy harvesting is a promising alternative for powering wireless electronics in many practical applications. Ambient vibration energy in the surrounding space of a target application often involves an inescapable randomness in the exciting vibrations, which may lead to deterioration of the expected power gains due to insufficient tuning and limited optimal designs. Stochastic resonance is a concept that has recently been considered for exploiting this randomness towards improving power generation from vibrating systems, based on the co-existence of near-harmonic vibrations with broadband noise excitations in a variety of practical mechanical systems. This paper is concerned with the optimal conditions for stochastic resonance in vibration energy harvesters, exploring the frequently neglected effect of realistic architectures of the electrical circuit on the system dynamics and the achievable power output. A parametric study is conducted using a numerical Path Integration method to compute the response Probability Density Functions of vibration energy harvesters, focusing on the effect of standard electrical components; namely, a load resistor, a rectifier and a capacitor. It is found that the conditions for stochastic resonance exhibit a nonlinear dependence on the weak harmonic excitation amplitude. Moreover, the modified nonlinear dissipation properties introduced by the rectifier and the capacitor lead to a trade-off between the power output and the non-conducting dynamics that is essential in order to determine optimal harvesting designs.

scholarly journals VIBRATION ENERGY HARVESTING TECHNIQUE: A COMPREHENSIVE REVIEW

2020 ◽  
Vol 4 (2) ◽  
pp. 46-48
Author(s):  
Nik Fakhri Nek Daud ◽  
Ruzlaini Ghoni
Keyword(s):  
Energy Harvesting ◽  
Power Output ◽  
Energy Conversion Efficiency ◽  
Vibration Energy Harvesting ◽  
Energy Harvesters ◽  
Output Performance ◽  
Harvesting Technique ◽  
External Power Source ◽  
External Power ◽  
Future Requirement

In order to minimize the requirement of external power source and maintenance for electric devices such as wireless sensor networks, the energy harvesting technique based on vibrations has been a dynamic field of studying interest over past years. Researchers have concentrated on developing efficient energy harvesters by adopting new materials and optimizing the harvesting devices. One important limitation of existing energy harvesting techniques is that the power output performance is seriously subject to the resonant frequencies of ambient vibrations, which are often random and broadband. This paper reviews important vibration-to-electricity conversion mechanisms, including theory, modelling methods and the realizations of the piezoelectric, electromagnetic and electrostatic approaches. Different types of energy harvesters that have been designed with nonlinear characteristics are also reviewed. As one of important factors to estimate the power output performance, the energy conversion efficiency of different conversion mechanisms is also summarized. Finally, the challenging issues based on the existing methods and future requirement of energy harvesting are also discussed.

scholarly journals Improving functionality of vibration energy harvesters using magnets

2012 ◽  
Vol 23 (13) ◽  
pp. 1433-1449 ◽  
Author(s):  
Lihua Tang ◽  
Yaowen Yang ◽  
Chee-Kiong Soh
Keyword(s):  
Experimental Study ◽  
Energy Harvesting ◽  
Transition Region ◽  
Parametric Study ◽  
Low Frequency ◽  
Design Guidelines ◽  
Vibration Energy ◽  
Vibration Energy Harvesting ◽  
Energy Harvesters ◽  
Low Frequency Vibration

In recent years, several strategies have been proposed to improve the functionality of energy harvesters under broadband vibrations, but they only improve the efficiency of energy harvesting under limited conditions. In this work, a comprehensive experimental study is conducted to investigate the use of magnets for improving the functionality of energy harvesters under various vibration scenarios. First, the nonlinearities introduced by magnets are exploited to improve the performance of vibration energy harvesting. Both monostable and bistable configurations are investigated under sinusoidal and random vibrations with various excitation levels. The optimal nonlinear configuration (in terms of distance between magnets) is determined to be near the monostable-to-bistable transition region. Results show that both monostable and bistable nonlinear configurations can significantly outperform the linear harvester near this transition region. Second, for ultra-low-frequency vibration scenarios such as wave heave motions, a frequency up-conversion mechanism using magnets is proposed. By parametric study, the repulsive configuration of magnets is found preferable in the frequency up-conversion technique, which is efficient and insensitive to various wave conditions when the magnets are placed sufficiently close. These findings could serve as useful design guidelines when nonlinearity or frequency up-conversion techniques are employed to improve the functionality of vibration energy harvesters.

Optimal Energy Harvesting From Impulse Trains Using Piezoelectric Transduction

2014 ◽  
Author(s):  
A. A. Kody ◽  
J. T. Scruggs
Keyword(s):  
Power Generation ◽  
Energy Harvesting ◽  
Low Frequency ◽  
Vibration Energy ◽  
Optimal Harvesting ◽  
Linear Quadratic ◽  
Vibration Energy Harvesting ◽  
Linear Quadratic Optimal Control ◽  
Vibration Energy Harvester ◽  
Harvesting Time

In applications of vibration energy harvesting to embedded wireless sensing, the available power and energy can be very low. This poses interesting challenges for technological feasibility if the parasitic losses in the electronics used to harvest this energy are prohibitive. In this study, we present a theory for the active control of power generation in energy harvesters in a manner which addresses and compensates for parasitic loss. We conduct the analysis in the context of a single-transducer piezoelectric bimorph cantilever beam subjected to a low-frequency impulse train. The power generation of the vibration energy harvester is maximized while considering mechanical losses, electrical losses, and the static power required to activate control intelligence and facilitate power-electronic conversion. It is shown that the optimal harvesting current can be determined through the use of linear quadratic optimal control techniques. The optimal harvesting time over which energy should be generated, following an impulse, is determined concurrently with the optimal feedback law. We show that this optimal harvesting time exhibits bifurcations as a function of the parameters characterizing the losses in the system.

On the stochastic dynamics of a nonlinear vibration energy harvester driven by Lévy flight excitations

2018 ◽  
Vol 30 (5) ◽  
pp. 945-967
Author(s):  
SUBRAMANIAN RAMAKRISHNAN ◽  
CONNOR EDLUND ◽  
COLLIN LAMBRECHT
Keyword(s):  
Energy Harvesting ◽  
Power Output ◽  
Stochastic Dynamics ◽  
Nonequilibrium Dynamics ◽  
Vibration Energy ◽  
Small Scale ◽  
Lévy Flight ◽  
Coupling Coefficients ◽  
Vibration Energy Harvesting ◽  
Levy Flight

Vibration energy harvesting aims to harness the energy of ambient random vibrations for power generation, particularly in small-scale devices. Typically, stochastic excitation driving the harvester is modelled as a Brownian process and the dynamics are studied in the equilibrium state. However, non-Brownian excitations are of interest, particularly in the nonequilibrium regime of the dynamics. In this work we study the nonequilibrium dynamics of a generic piezoelectric harvester driven by Brownian as well as (non-Brownian) Lévy flight excitation, both in the linear and the Duffing regimes. Both the monostable and the bistable cases of the Duffing regime are studied. The first set of results demonstrate that Lévy flight excitation results in higher expectation values of harvested power. In particular, it is shown that increasing the noise intensity leads to a significant increase in power output. It is also shown that a linearly coupled array of nonlinear harvesters yields improved power output for tailored values of coupling coefficients. The second set of results show that Lévy flight excitation fundamentally alters the bifurcation characteristics of the dynamics. Together, the results underscore the importance of non-Brownian excitation characterised by Lévy flight in vibration energy harvesting, both from a theoretical viewpoint and from the perspective of practical applications.

Towards a Self-Tunable, Wide Frequency Bandwidth Vibration Energy Harvesting Device

2009 ◽  
Author(s):  
Vinod R. Challa ◽  
M. G. Prasad ◽  
Frank T. Fisher
Keyword(s):  
Energy Harvesting ◽  
Resonance Frequency ◽  
Power Output ◽  
Frequency Tuning ◽  
Cutoff Frequency ◽  
Peak Power Output ◽  
Vibration Energy ◽  
Frequency Bandwidth ◽  
Vibration Energy Harvesting ◽  
Ultra Low Power

Vibration energy harvesting is increasing in popularity due to potential applications such as powering wireless sensors and ultra low power devices. For efficient energy harvesting, matching the device frequency to the source frequency is a major design requirement. Since mechanical vibrations differ in characteristics (frequency and acceleration amplitude), it is difficult to design an individual energy harvesting device for every source. Recently, several groups have pursued techniques to tune the resonance frequency of the vibrating structure through active and passive methods. In this paper, work has been done to attain a self-tunable energy harvesting device, which utilizes a magnetic force resonance frequency tuning technique to tune the device. The device is successfully tuned with in a bandwidth of ± 27% of its untuned resonance frequency, considering root mean square of the peak power output as the cutoff for frequency bandwidth. Since the technique is semi-active, energy is only consumed to tune the resonance frequency and is not required to remain at that specific frequency. The device consists of a piezoelectric cantilever beam array which is displaced to the desired distance to induce magnetic stiffness and to match the source frequency using a DC motor. The device has a power output of approximately 0.7 mW to 1 mW in the designed cutoff frequency range. The amount of energy consumed by the actuator to displace the beam is approximately 3.5 W to 4.5 W, which requires approximately 150 minutes to reclaim the expended energy.

scholarly journals A Review of Piezoelectric Vibration Energy Harvesting with Magnetic Coupling Based on Different Structural Characteristics

Micromachines ◽  
2021 ◽  
Vol 12 (4) ◽  
pp. 436
Author(s):  
Junxiang Jiang ◽  
Shaogang Liu ◽  
Lifeng Feng ◽  
Dan Zhao
Keyword(s):  
Energy Harvesting ◽  
Magnetic Force ◽  
Structural Characteristics ◽  
Magnetic Coupling ◽  
Vibration Energy ◽  
Vibration Energy Harvesting ◽  
Energy Harvesters ◽  
Harvesting Efficiency ◽  
Energy Harvesting Efficiency ◽  
Piezoelectric Vibration

Piezoelectric vibration energy harvesting technologies have attracted a lot of attention in recent decades, and the harvesters have been applied successfully in various fields, such as buildings, biomechanical and human motions. One important challenge is that the narrow frequency bandwidth of linear energy harvesting is inadequate to adapt the ambient vibrations, which are often random and broadband. Therefore, researchers have concentrated on developing efficient energy harvesters to realize broadband energy harvesting and improve energy-harvesting efficiency. Particularly, among these approaches, different types of energy harvesters adopting magnetic force have been designed with nonlinear characteristics for effective energy harvesting. This paper aims to review the main piezoelectric vibration energy harvesting technologies with magnetic coupling, and determine the potential benefits of magnetic force on energy-harvesting techniques. They are classified into five categories according to their different structural characteristics: monostable, bistable, multistable, magnetic plucking, and hybrid piezoelectric–electromagnetic energy harvesters. The operating principles and representative designs of each type are provided. Finally, a summary of practical applications is also shown. This review contributes to the widespread understanding of the role of magnetic force on piezoelectric vibration energy harvesting. It also provides a meaningful perspective on designing piezoelectric harvesters for improving energy-harvesting efficiency.

Transfer Function Analysis of Constrained, Distributed Piezoelectric Vibration Energy Harvesting Beam Systems

2018 ◽  
Vol 140 (3) ◽  
Author(s):  
Chin An Tan ◽  
Shahram Amoozegar ◽  
Heather L. Lai
Keyword(s):  
Energy Harvesting ◽  
Transfer Function ◽  
Boundary Conditions ◽  
Vibration Energy ◽  
System Response ◽  
Vibration Energy Harvesting ◽  
Energy Harvesters ◽  
Piezoelectric Energy ◽  
Transfer Function Analysis ◽  
Intermediate Constraints

This paper presents a novel formulation and exact solution of the frequency response function (FRF) of vibration energy harvesting beam systems by the distributed transfer function method (TFM). The method is applicable for coupled electromechanical systems with nonproportional damping, intermediate constraints, and nonclassical boundary conditions, for which the system transfer functions are either very difficult or cumbersome to obtain using available methods. Such systems may offer new opportunities for optimized designs of energy harvesters via parameter tuning. The proposed formulation is also systematic and amenable to algorithmic numerical coding, allowing the system response and its derivatives to be computed by only simple modifications of the parameters in the system operators for different boundary conditions and the incorporation of feedback control principles. Examples of piezoelectric energy harvesters with nonclassical boundary conditions and intermediate constraints are presented to demonstrate the efficacy of the proposed method and its use as a design tool for vibration energy harvesters via tuning of system parameters. The results can also be used to provide benchmarks for assessing the accuracies of approximate techniques.

MEMS Energy Harvesting from Low-frequency and Low-g Vibrations

2015 ◽  
Vol 1782 ◽  
pp. 9-14
Author(s):  
Ruize Xu ◽  
Sang-Gook Kim
Keyword(s):  
Residual Stress ◽  
Energy Harvesting ◽  
Autonomous Systems ◽  
Scale Model ◽  
Vibration Energy ◽  
Frequency Range ◽  
Mechanical Resonator ◽  
Vibration Energy Harvesting ◽  
Energy Harvesters ◽  
Working Frequency

ABSTRACTMEMS vibration energy harvesting has been investigated to provide energy to low-power micro-electronic systems and potentially to enable batteryless autonomous systems. While enjoying the small footprint hence the ability to be embedded in other systems, MEMS vibration energy harvesters are working at much higher frequencies and input vibration amplitudes. The mechanical resonator based energy harvesters seem inherently have such high frequency due to the scaling of the device dimension. Lower the working frequency range and input vibration amplitude are possible by optimizing the dimensions of the device. However, we are viewing the problem from a different perspective and proposing a solution based on employing the common material property of the micro-fabricated thin film – residual stress. We found that by taking advantage of the compressive residual stress, a bi-stable mechanical resonator could be built and a new spectrum of dynamics can be brought into energy harvesting, which could lower the working frequency range and input g value. The concepts have been analytically simulated and experimentally verified by a meso-scale model.

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