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The purpose of this paper is to present the design of a piezoelectric vibration energy generator with a power conditioning circuit to power a wireless sensor node. Frequency and voltage characterization of the piezoelectric energy harvester is performed. A single-stage AC–DC power converter that integrates the rectification and boosting circuit is designed, simulated and implemented in hardware.

The designed power conditioning circuit incorporates bridgeless boost rectification, a lithium ion battery as an energy storage unit and voltage regulation to extract maximum power from PZT-5H and to attain higher efficiency. The sensor node is modelled in active and sleep states on the basis of the power consumption. Dynamic modelling of the lithium ion battery with its state of charging and discharging is analysed.

The test result shows that the energy harvester produces a maximum power of 65.9 mW at the resonant frequency of 21.4 Hz. The designed circuit will operate even at a minimum input voltage of 0.5 V. The output from the harvester is rectified, boosted to a 7-V DC output and regulated to 3.3 V to the power C_Mote wireless sensor node. The conversion efficiency of the circuit is improved to 70.03 per cent with a reduced loss of 19.76 mW.

The performance of the energy harvester and the single-stage power conditioning circuit is analysed. Further, the design and implementation of the proposed circuit lead to an improved conversion efficiency of 70.03 per cent with a reduced loss of 19.76 mW. The vibration energy harvester is integrated with a power conditioning circuit to power a wireless sensor node C_Mote. The piezoelectric vibration energy harvester is implemented in real time to power C_Mote.

This paper aims to design an optimum vertical axis wind turbine (VAWT) and assess its techno-economic performance for wind energy harvesting at high-speed railway in Malaysia.

This project adopted AutoCAD and ANSYS modeling tools to design and optimize the blade of the turbine. The site selected has a railway of 30 km with six stops. The vertical turbines are placed 1 m apart from each other considering the optimum tip speed ratio. The power produced and net present value had been analyzed to evaluate its techno-economic viability.

Computational fluid dynamics (CFD) analysis of National Advisory Committee for Aeronautics (NACA) 0020 blade has been carried out. For a turbine with wind speed of 50 m/s and swept area of 8 m², the power generated is 245 kW. For eight trains that operate for 19 h/day with an interval of 30 min in nonpeak hours and 15 min in peak hours, total energy generated is 66 MWh/day. The average cost saved by the train stations is RM 16.7 mil/year with battery charging capacity of 12 h/day.

Wind energy harvesting is not commonly used in Malaysia due to its low wind speed ranging from 1.5 to 4.5 m/s. Conventional wind turbine requires a minimum cut-in wind speed of 11 m/s to overcome the inertia and starts generating power. Hence, this paper proposes an optimum design of VAWT to harvest an unconventional untapped wind sources from railway. The research finding complements the alternate energy harvesting technologies which can serve as reference for countries which experienced similar geographic constraints.

This paper aims to study a power management circuit for a piezoelectric vibration energy harvester. It presents how to accumulate energy and provide regulated DC voltage for practical applications.

Energy storage and extraction circuit are proposed. While the storage stage consists of a full wave rectifier and a storage capacitor, the extraction stage includes a voltage comparator and regulator, which may provide the load steady DC voltage when the voltage of the storage capacitor is higher than the threshold.

The numerical analysis and experimental results indicate that it takes a longer time to charge to a specified voltage for the greater storage capacitor and the net charge flowing into the storage capacitor during each period decreases when the voltage of the storage capacitor is higher. The higher threshold voltage of the capacitor has lower harvesting efficiency owing to the rate of charging of the storage capacitor slowing down over time.

Because of the chosen research method, the power management circuit is only suitable for the piezoelectric vibration energy harvester under resonant conditions.

This study includes practically useful applications for users to build a power management circuit for piezoelectric energy harvester.

This study presents results that the charging efficiency of the storage circuit is relative to the storage capacitor and the threshold voltage.

The paper aims to analyze the behavior of the Galfenol rods under bending conditions that are employed in a vibration energy harvester by illustrating the spatial variations in stress and magnetic field.

This paper describes a 3‐D static finite element model of magnetostrictive materials, considering magnetic and elastic boundary value problems that are bidirectionally coupled through stress and field dependent variables. The finite element method is applied to a small vibration‐driven generator of magnetostrictive type employing Iron‐Gallium alloy (Galfenol).

The 3‐D static finite element modeling presented here highlights the spatial variations in magnetic field and relative permeability due to the corresponding stress distribution in the Galfenol rods subjected to transverse load. The numerical calculations show that about 1.1 T change in magnetic flux density is achieved which demonstrates the effectiveness of the inspected vibration‐driven generator in voltage generation and energy harvesting. The model predictions agree with the experimental results and are coherent with the magnetostriction phenomenon.

This paper fulfils the behavior analysis of Galfenol rods under transverse load that includes both compression and tension. The compressive and tensile stresses contributions to change in magnetic flux densities in the Galfenol rods were calculated by which the effectiveness of the inspected vibration‐driven generator in voltage generation and energy harvesting is demonstrated.

The purpose of this study is to develop a friction-type energy-harvesting device based on magnetic liquids (MLs). This MLs energy-harvesting device combines MLs with a triboelectric nanogenerator (TENG), reducing the friction thermal effect to improve the conversion efficiency and working frequency band.

First, the motion equation of the MLs is calculated using the Bernoulli and fluid continuity equations. Second, the sloshing process of an ML in a container is simulated using the finite element simulation method, and the magnetic field distribution of the permanent magnet in the MLs is calculated. Then, the output characteristic of the ML-TENG is deduced theoretically, and the influencing factors of the output voltage are analyzed. Finally, the output voltage of the MLs energy-harvesting device was tested experimentally, and the influence of the magnetic field on the output voltage was tested.

This study proposes a vibration energy harvesting device based on MLs. The output voltage of the device was obtained through simulation and experimental tests, and the effect of the magnetic field on the output voltage was obtained.

This study provides a method to convert vibration energy into electrical energy using the magnetic response and fluid characteristics of MLs, and the availability of the device is verified by simulation and experiment. This energy-harvesting device exhibits less loss and a more sensitive response.

This paper aims to present the design of a cantilever beam with various kinds of geometries for application in energy harvesting devices with a view to enhance the harvested power. The cantilever beams in rectangular, triangular and trapezoidal geometries are simulated, designed and evaluated experimentally. A power conditioning circuit is designed and fabricated for rectification and regulation.

The analytical model based on Euler–Bernoulli beam theory is analyzed for various cantilever geometries. The aluminum beam with Lead Zirconate Titanate (PZT) 5H strip is used for performing frequency, displacement, strain distribution, stress and potential analysis. A comparative analysis is done based on the estimated performance of the cantilevers with different topologies of 4,500 mm³ volume.

The analysis shows the trapezoidal cantilever yielding a maximum voltage of 66.13 V at 30 Hz. It exhibits maximum power density of 171.29 W/mm³ at optimal resistive load of 330 kΩ. The generated power of 770.8 µW is used to power up a C-mote wireless sensor network.

This study provides a complete structural analysis and implementation of the cantilever for energy harvesting application, integration of power conditioning circuit with the energy harvester and evaluation of the designed cantilevers under various performance metrics.

The purpose of this paper is to report the study of vibration energy harvesting from a data center (DC) mainframe computer to power nodes of a wireless sensors network (WSN are used to improve the energy efficiency of a DC).

The piezoelectric vibration energy harvester (VEH) has been designed using an electromechanical analytical model. The VEH is composed of a three-layer cantilever beam with a tip mass. A vibration map (amplitude and acceleration) is presented and the authors show that the optimum frequency is around 90 Hz with maximum amplitude of 1 μm and maximum acceleration of 0.6 m/s2. Modeling results and experimental measurements using an electromagnetic shaker to apply vibrations concord.

The VEH delivers a maximum power of 31 μW on a DC mainframe computer and 2.3 mW at 1g on a test rack. It allows us to use a storage capacitance to successfully power a wireless sensor node for measuring temperature. This paper has been carried out in cooperation with IBM Montpellier and within the framework of the RIDER project financed by the French government and the European Union.

A vibration map (amplitude and acceleration) is presented and the authors show that the optimal frequency is around 90 Hz with maximum amplitude of 1 μm and maximum acceleration of 0.6 m/s2. The VEH delivers a maximum power of 31 μW on DC mainframe computer and 2.3 mW at 1 g on test mounted the shaker. It allows us with a storage capacitance to successfully power a wireless sensor node for measuring temperature.

The finite element method (FEM) for 3D models needs heavy computational cost. The computational cost for FE analysis of moving objects, e.g. Vibration energy harvester, must be reduced to exploit the simulation of the dynamic system in its design. The paper aims to discuss these issues.

To reduce the computational time of FEM, the model order reduction (MOR) based on proper orthogonal decomposition has been proposed. For the moving systems, MOR is modified.

It is shown that proposed MOR makes it possible to drastically reduce the coupling analysis of the energy harvester in which the equations of motion, magnetostatics, and circuit are repeatedly solved.

To reduce the computational time of FEM, block-MOR is presented, in which the whole domain is subdivided into N-blocks. As a result computational cost for MOR can be reduced.

A three-dimensional finite element (FE) model is developed to design a vibrating bimorph piezoelectric cantilever beam with lead zirconate titanate (PZT-5H) for energy harvesting. The paper aims to discuss these issues.

A parametric study of electric power generated as a function of the dielectric constant, transverse piezoelectric strain constant, length and thickness of the piezoelectric material, is conducted for a time-harmonic surface pressure load. Transversely isotropic elastic and piezoelectric properties are assigned to the bimorph layers with brass chosen as the substrate material in the three-dimensional FE model. Using design of experiments, a study was conducted to determine the sensitivity of power with respect to the geometric and material variables.

The numerical analysis shows that a uniform decrease in thickness and length coverage of the piezoelectric layers results in a nonlinear reduction in power amplitude, which suggests optimal values. The piezoelectric strain coefficient, d31 and the thickness of PZT-5H, tp, are the most important design parameters to generate high electric energy for bimorph vibration harvesting device.

The work demonstrates that, through a sensitivity analysis, the electro-mechanical piezoelectric coupling coefficient (d31) and the thickness of the piezoelectric strips (tp) are the most important parameters which have a significant effect on power harvested.

The purpose of this paper is to demonstrate the feasibility of using kinetic energy harvesting to power wireless condition monitoring sensors.

The system presented duty cycles its operation depending upon the energy being harvested. The harvested energy is stored on a supercapacitor and the system samples sufficient vibration data to enable an FFT to be performed at the receiver.

The results of this study show it is perfectly feasible to power practical wireless condition monitoring sensors entirely from the vibrations of the machines being monitored.

Energy harvesting techniques can be used to power wireless sensors in a range of applications. Removing the need for a battery power supply presents obvious environmental benefits and avoids the need to periodically replace batteries.