Analysis of energy harvesters for highway bridges

2011 ◽  
Vol 22 (16) ◽  
pp. 1929-1938 ◽  
Author(s):  
S. F. Ali ◽  
M. I. Friswell ◽  
S. Adhikari
Keyword(s):  
Average Power ◽  
Highway Bridges ◽  
Point Load ◽  
Structural Vibration ◽  
Energy Scavenging ◽  
Single Degree Of Freedom ◽  
Energy Harvesters ◽  
Piezoelectric Energy ◽  
Bridge Model ◽  
Single Vehicle

This article investigates the possibility of piezoelectric energy harvesters as energy scavenging devices in highway bridges. The structural vibration due to the motion of a load (vehicle) on the bridge is considered as the source of energy generation for the harvester. The energy generated in this way can be useful for wireless sensor networks for structural health monitoring of bridges by reducing or even eliminating the need for battery replacement/recharging. A highway bridge model with a moving point load is investigated and a linear single-degree-of-freedom model is used for the piezoelectric energy harvester. Two types of harvesters, namely, the harvesting circuit with and without an inductor, have been considered and the energy generated for a single vehicle has been estimated. These results may be used, together with traffic statistics, to obtain the variation of average power and thus, for a given application, help to design the energy management system.

Model Reduction of Piezoelectric Energy Harvesters Subject to Band-Limited, Stochastic Base Excitation

2012 ◽  
Author(s):  
Adam M. Wickenheiser
Keyword(s):  
White Noise ◽  
Design Optimization ◽  
Broadband Noise ◽  
Degree Of Freedom ◽  
Single Degree Of Freedom ◽  
Energy Harvesters ◽  
White Noise Excitation ◽  
Single Degree ◽  
Piezoelectric Energy ◽  
Band Limited

In many scenarios where vibration energy harvesting can be utilized — particularly those involving bio-motions or environmental disturbances — energy sources are broadband and non-stationary. On the other hand, design procedures have been predominantly developed for harmonic or white noise excitation, specifically for single degree of freedom approximations of the transducer. In this paper, a general approach for design optimization of cantilevered, piezoelectric energy harvesters in the presence of band-limited, white-noise excitation is outlined. For this study, human and vehicular motions are considered; these complex waveforms are distilled into a small set of dominant features with regard to their impact on the power output of the device. Criteria based on modal participation factors, including pre-filtering of the disturbance, are used in guiding the reduction of the input and plant degrees of freedom in order to make the design optimization problem tractable. This process determines the error in assuming a low-order model for the transducer in the presence of broadband noise that may excite multiple modes of vibration. Furthermore, this study considers the quantitative impact of charge cancellation in higher modes and the benefits of inserting multiple electrodes along the length. To illustrate these methods, energy harvesters are designed for acceleration data collected from walking and car idling. It is shown that a simple method that is a generalization of naïve approaches that assume harmonic or white noise excitation and a single degree of freedom can determine which simplifications are appropriate and the inaccuracies that can be expected from them.

scholarly journals The State-of-the-Art Brief Review on Piezoelectric Energy Harvesting from Flow-Induced Vibration

2021 ◽  
Vol 2021 ◽  
pp. 1-19
Author(s):  
Hongjun Zhu ◽  
Tao Tang ◽  
Huohai Yang ◽  
Junlei Wang ◽  
Jinze Song ◽  
...  
Keyword(s):  
Energy Harvesting ◽  
Bluff Body ◽  
Mechanical Energy ◽  
Wake Flow ◽  
Structural Vibration ◽  
Small Scale ◽  
Flow Induced Vibration ◽  
Energy Harvesters ◽  
Piezoelectric Energy ◽  
Self Powered

Flow-induced vibration (FIV) is concerned in a broad range of engineering applications due to its resultant fatigue damage to structures. Nevertheless, such fluid-structure coupling process continuously extracts the kinetic energy from ambient fluid flow, presenting the conversion potential from the mechanical energy to electricity. As the air and water flows are widely encountered in nature, piezoelectric energy harvesters show the advantages in small-scale utilization and self-powered instruments. This paper briefly reviewed the way of energy collection by piezoelectric energy harvesters and the various measures proposed in the literature, which enhance the structural vibration response and hence improve the energy harvesting efficiency. Methods such as irregularity and alteration of cross-section of bluff body, utilization of wake flow and interference, modification and rearrangement of cantilever beams, and introduction of magnetic force are discussed. Finally, some open questions and suggestions are proposed for the future investigation of such renewable energy harvesting mode.

scholarly journals Experimental Characterization of Optimized Piezoelectric Energy Harvesters for Wearable Sensor Networks

Sensors ◽  
2021 ◽  
Vol 21 (21) ◽  
pp. 7042
Author(s):  
Petar Gljušćić ◽  
Saša Zelenika
Keyword(s):  
Sensor Networks ◽  
Kinetic Energy ◽  
Average Power ◽  
Wearable Devices ◽  
Specific Power ◽  
Medical Systems ◽  
Power Sources ◽  
Energy Harvesters ◽  
Piezoelectric Energy ◽  
Power Outputs

The development of wearable devices and remote sensor networks progressively relies on their increased power autonomy, which can be further expanded by replacing conventional power sources, characterized by limited lifetimes, with energy harvesting systems. Due to its pervasiveness, kinetic energy is considered as one of the most promising energy forms, especially when combined with the simple and scalable piezoelectric approach. The integration of piezoelectric energy harvesters, generally in the form of bimorph cantilevers, with wearable and remote sensors, highlighted a drawback of such a configuration, i.e., their narrow operating bandwidth. In order to overcome this disadvantage while maximizing power outputs, optimized cantilever geometries, developed using the design of experiments approach, are analysed and combined in this work with frequency up-conversion excitation that allows converting random kinetic ambient motion into a periodical excitation of the harvester. The developed optimised designs, all with the same harvesters’ footprint area of 23 × 15 mm, are thoroughly analysed via coupled harmonic and transient numerical analyses, along with the mostly neglected strength analyses. The models are validated experimentally via innovative experimental setups. The thus-proposed f = 50 mm watch-like prototype allows, by using a rotating flywheel, the collection of low-frequency (ca. 1 to 3 Hz) human kinetic energy, and the periodic excitation of the optimized harvesters that, oscillating at their eigenfrequencies (~325 to ~930 Hz), display specific power outputs improved by up to 5.5 times, when compared to a conventional rectangular form, with maximal power outputs of up to >130 mW and average power outputs of up to >3 mW. These power levels should amply satisfy the requirements of factual wearable medical systems, while providing also an adaptability to accommodate several diverse sensors. All of this creates the preconditions for the development of novel autonomous wearable devices aimed not only at sensor networks for remote patient monitoring and telemedicine, but, potentially, also for IoT and structural health monitoring.

Efficient and Sensitive Energy Harvesting Using Piezoelectric MEMS Compliant Mechanisms

2015 ◽  
Author(s):  
Xiaokun Ma ◽  
Hong Goo Yeo ◽  
Christopher D. Rahn ◽  
Susan Trolier-McKinstry
Keyword(s):  
Proof Mass ◽  
Compliant Mechanisms ◽  
Compliant Mechanism ◽  
Average Power ◽  
Low Frequency ◽  
Human Movement ◽  
Energy Harvesters ◽  
Piezoelectric Energy ◽  
Rigid Frame ◽  
The Time Domain

Piezoelectric energy harvesters typically perform poorly in the low frequency, low amplitude, and intermittent excitation environment of human movement. In this paper, a piezoelectric compliant mechanism (PCM) energy harvester is designed, modeled, and analyzed that consists of a PZT unimorph clamped at the base and attached to a compliant mechanism at the tip. The compliant mechanism has two flexures that amplify the tip displacement to produce large motion of a proof mass and a low frequency first mode with an efficient (nearly quadratic) shape. The compliant mechanism is fabricated as a separate, relatively rigid frame with flexure hinges, simplifying the fabrication process and surrounding and protecting the PZT unimorph. The bridge structure of the PCM also introduces an axial tensioning nonlinearity that self-limits the response to large amplitude impacts, improving the robustness of the device. Comparing the time domain performance based on realistic wrist acceleration data, the PCM produces 6 times more average power than a proof mass cantilever with the same unimorph area and natural frequency.

Scavenging energy from a vibrating building using distributed electromagnetic energy harvesters with nonlinear circuits

2021 ◽  
pp. 1045389X2199088
Author(s):  
Cheng Ning Loong ◽  
Chih-Chen Chang
Keyword(s):  
Output Power ◽  
Short Circuit ◽  
Random Excitation ◽  
Electromagnetic Energy ◽  
Nonlinear Circuits ◽  
Structural Vibration ◽  
Statistical Linearization ◽  
Energy Scavenging ◽  
Energy Harvesters ◽  
Story Building

The energy scavenged from a vibrating building installed with distributed electromagnetic energy harvesters under random excitation is analyzed. Each harvester is connected to an energy harvesting circuit made of a full-wave bridge rectifier connecting a resistor in parallel with a capacitor. Statistical linearization is adopted to estimate the stationary response of the harvester-structure system. As an illustrative example, a 20-story building equipped with 16 harvesters on each story is examined. Results show that the scavenged energy mainly concentrates at the higher stories. The vibration mitigation and energy scavenging performance of the harvesters can be enhanced simultaneously with the proper design of harvesters and circuits. Gradient ascent approach with the first-order perturbation approximation is proposed to determine the optimal design of distributed harvesters with nonlinear circuits that maximizes the total mean output power. Results show that output power decreases due to circuit nonlinearity. The maximum total mean output power obtained from the 20-story building under wind excitations with mean speed of 5 m/s is around 1.32–2.17 kW for harvesters having short-circuit damping coefficient ranging 100–300 kNs/m. These results show that scavenging energy from structural vibration is a feasible technology even considering the negative effect of circuit nonlinearity.

Efficient Aeroelastic Energy Harvesting From HVAC Ducts

2015 ◽  
Author(s):  
Xiaokun Ma ◽  
Christopher D. Rahn
Keyword(s):  
Cantilever Beam ◽  
Average Power ◽  
Beam Theory ◽  
Constitutive Law ◽  
Premature Failure ◽  
Energy Harvesters ◽  
Piezoelectric Energy ◽  
Higher Power ◽  
Pressure Dynamics ◽  
Euler Bernoulli Beam

Piezoelectric energy harvesters can be used to scavenge energy for unattended sensors in heating ventilation and air conditioning (HVAC) ducts. In this paper, an aeroelastic energy harvester using a pinned-pinned beam is designed, modeled, and analyzed. To obtain the desired model, we use nonlinear Euler-Bernoulli beam theory, a linear piezoelectric constitutive law, and nonlinear pressure dynamics. Compared with the traditional cantilever beam used by previous researchers, the pinned-pinned beam has a higher frequency limit cycle and more efficient mode shape, which ensure higher power output at the same strain level. The pinned-pinned boundary condition also self-limits the response amplitude, limiting strain in the piezoelectric beam and premature failure. Simulation results show that the pinned-pinned beam can harvest at least 4 times more average power than a cantilever beam with the same maximum strain.

scholarly journals Effects of Electrical and Electromechanical Parameters on Performance of Galloping-Based Wind Energy Harvester with Piezoelectric and Electromagnetic Transductions

Vibration ◽  
2019 ◽  
Vol 2 (2) ◽  
pp. 222-239 ◽  
Author(s):  
Hongyan Wang ◽  
Liya Zhao ◽  
Lihua Tang
Keyword(s):  
Wind Energy ◽  
Analytical Solutions ◽  
Power Output ◽  
Parametric Study ◽  
Energy Harvester ◽  
Numerical Solutions ◽  
Average Power ◽  
Energy Harvesters ◽  
Piezoelectric Energy ◽  
Approximate Analytical Solutions

This paper presents an analysis of galloping-based wind energy harvesters with piezoelectric and electromagnetic transductions. The lumped parameter models of the galloping-based piezoelectric energy harvester (GPEH) and galloping-based electromagnetic energy harvester (GEMEH) are developed and the approximate analytical solutions of the equations are derived using the harmonic balance method (HBM). The accuracy of the approximate analytical solutions is validated by the numerical solutions. A parametric study is then conducted based on the validated models and solutions to understand the effects of the dimensionless load resistance, r, and electromechanical coupling strength (EMCS) on various quantities indicating the performance of the harvesters, including the dimensionless oscillating frequency, cut-in wind speed, displacement, and average power output. The results show that both r and EMCS can affect the dimensionless oscillating frequencies of the GPEH and GEMEH in a narrow frequency range around the natural frequency. A significant decrease in the displacement around r = 1 for GEPH and at a low r for GEMEH indicates the damping effect induced by the increase in EMCS. There are two optimal r to achieve the maximal power output for GPEH given strong EMCS while there is only one optimal r for GEMEH. Both GPEH and GEMEH show similar characteristics in that the optimal power outputs can reach saturation with an increase of the EMCS. The findings from the parametric study provide useful guidelines for the design of galloping-based energy harvesters with different energy conversion mechanisms.

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