Power Analysis for Piezoelectric Energy Harvester

Smart Materials and Structures, 2006

Power harvesting refers to the practice of acquiring energy from the environment which would be otherwise wasted and converting it into usable electric energy. Much work has been done on studying the optimal AC power output, while little has considered the AC-DC output. This article investigates the optimal AC-DC power generation for a rectified piezoelectric device. In contrast with estimates based on various degrees of approximation in the recent literature, an analytic expression for the AC-DC power output is derived under steady-state operation. It shows that the harvested power depends on the input vibration characteristics (frequency and acceleration), the mass of the generator, the electrical load, the natural frequency, the mechanical damping ratio and the electromechanical coupling coefficient of the system. An effective power normalization scheme is provided to compare the relative performance and efficiency of devices. The theoretical predictions are validated and found to be in good agreement with both experimental observations and numerical simulations. Finally, several design guidelines are suggested for devices with large coupling coefficient and quality factor.

International Journal of Applied Science, 2018

In this paper, a new method is proposed for improving a piezoelectric energy harvester’s output power. A piezoelectric vibration energy harvester has an inherent internal capacitance. The new approach adopts inductance to reduce the reactance of the internal capacitance and enhance the output power. To show the practicality of this method, four electrical circuits are investigated numerically and experimentally for a piezoelectric beam energy harvester: Simple Resistive Load, Inductive Load, standard AC-DC, and Inductive AC-DC circuits. An Inductive Load circuit is built by adding an inductor to a Simple Resistive Load circuit, while an Inductive AC-DC circuit is built by adding an inductor to a standard AC-DC circuit. Experimental results indicate that the Inductive Load and the Inductive AC-DC circuits avail the Simple Resistive Load and standard AC-DC circuits respectively. The inductive AC-DC circuit shows a 6.7% increase in the output power compared to the standard AC-DC circuit.

IEEE Transactions on Industrial Electronics, 2010

The behavior of a piezoelectric vibration-driven energy harvester with different power processing circuits is evaluated. Two load types are considered: a resistive load and an ac-dc rectifier load. An optimal resistive and optimal dc-voltage load for the harvester is analytically calculated. The difference between the optimal output power flow from the harvester to both load circuits depends on the coupling coefficient of the harvester. Two power processing circuits are designed and built, the first emulating a resistive input impedance and the second with a constant input voltage. It is shown that, in order to design an optimal harvesting system, the combination of both the ability of the circuit to harvest the optimal harvester power and the processing circuit efficiency needs to be considered and optimized. Simulations and experimental validation using a custom-made piezoelectric harvester show that the efficiency of the overall system is 64% with a buck converter as a power processing circuit, whereas an efficiency of only 40% is reached using a resistor-emulating approach.

Mechanical Engineering Scientific Journal, 2023

Energy harvesting by using piezoelectric materials is one of the most widely used techniques for conversion of waste energy into useful. Using this technique, generated vibration energy from machines can be converted into useful electrical energy. In this paper, an energy harvesting system that supplies power for low-power consumption devices has been designed. The experimental model consists of a rotating machine that generates mechanical vibrations that actuate a cantilever beam and a piezoelectric transducer as a sensor for energy harvesting. The aim is to generate greater power as an output, which could be achieved by obtaining maximal strain for the given frequency range of the vibration source. The frequency range of the vibration machine is variable and multiple frequencies have been used. Using the Euler-Bernoulli method, the beam dimensions have been calculated so that its natural frequency matches the operating machine frequency. By reaching the resonant point of the cantilever beam, the maximal power from the designed energy harvesting system can be generated.

This review paper focuses on one of the progressive method of energy harvesting using piezoelectric material. Energy Harvesting is a process of capturing energy surrounding system such as vibration and converted that vibration into electrical energy. In this paper we are using a piezoelectric material for harvesting a power. There are two types of piezoelectric material such as crystal and ceramics. Piezoelectric material has two properties, first one is when a mechanical force is applied on any piezoelectric material it produces an electric charge on it and another one is when a electrical force is applied on piezoelectric material it produces a mechanical distortion. I.e. it converts a mechanical vibration into electrical energy. Energy generation from conventional sources it being polluted hence power generation from piezoelectric material is free from environmental pollution.

Shock and Vibration Digest, 2004

The process of acquiring the energy surrounding a system and converting it into usable electrical energy is termed power harvesting. In the last few years, there has been a surge of research in the area of power harvesting. This increase in research has been brought on by the modern advances in wireless technology and low-power electronics such as microelectromechanical systems. The advances have allowed numerous doors to open for power harvesting systems in practical real-world applications. The use of piezoelectric materials to capitalize on the ambient vibrations surrounding a system is one method that has seen a dramatic rise in use for power harvesting. Piezoelectric materials have a crystalline structure that provides them with the ability to transform mechanical strain energy into electrical charge and, vice versa, to convert an applied electrical potential into mechanical strain. This property provides these materials with the ability to absorb mechanical energy from their surroundings, usually ambient vibration, and transform it into electrical energy that can be used to power other devices. While piezoelectric materials are the major method of harvesting energy, other methods do exist; for example, one of the conventional methods is the use of electromagnetic devices. In this paper we discuss the research that has been performed in the area of power harvesting and the future goals that must be achieved for power harvesting systems to find their way into everyday use.

2013

This paper presents a micro-electro-mechanical system (MEMS) piezoelectric power generator array for vibration energy harvesting. A complete design flow of the vibration-based energy harvester using the finite element method (FEM) is proposed. The modal analysis is selected to calculate the resonant frequency of the harvester, and harmonic analysis is performed to investigate the influence of the geometric parameters on the output voltage. Based on simulation results, a MEMS Pb(Zr,Ti)O 3 (PZT) cantilever array with an integrated large Si proof mass is designed and fabricated to improve output voltage and power. Test results show that the fabricated generator, with five cantilever beams (with unit dimensions of about 3 × 2.4 × 0.05 mm 3) and an individual integrated Si mass dimension of about 8 × 12.4 × 0.5 mm 3 , produces a output power of 66.75 μW, or a power density of 5.19 μW•mm −3 •g −2 with an optimal resistive load of 220 kΩ from 5 m/s 2 vibration acceleration at its resonant frequency of 234.5 Hz. In view of high internal impedance characteristic of the PZT generator, an efficient autonomous power conditioning circuit, with the function of impedance matching, energy storage and voltage regulation, is then presented, finding that the efficiency of the energy storage is greatly improved and up to 64.95%. The proposed self-supplied energy generator with power conditioning circuit could provide a very promising complete power supply solution for wireless sensor node loads.

Due to the development of ultra-low power portable electronics and wireless sensors, the use of ambient energy, such as vibration energy for harvesting energy using piezoelectric materials has aroused great interests. A number of techniques have been proposed by the researchers for harvesting energy from the vibration source. Mostly, the techniques are classified as narrowband or broadband depending on the range of frequencies in which they produce maximum power. Substantial research has been done by the researchers in both these areas and countless techniques are proposed in order to harvest maximum power. A study is needed to compare these techniques to suggest a proper technique for a typical application. This paper presents a detailed categorization of the various piezoelectric energy harvesting techniques and also covering each of them with suitable examples. The pros and cons of each technique are also presented.

Journal de Physique IV (Proceedings), 2005

This paper compares the performances of vibration-powered electrical generators using a piezoelectric ceramic and a piezoelectric single crystal associated to several power conditioning interfaces. A new approach of the piezoelectric power conversion based on a non linear voltage processing is presented, leading to three novel high-performance techniques. Theoretical predictions and experimental results show that the novel techniques may increase the power harvested above 800% compared to standard techniques.

IEEE Transactions on Ultrasonics, Ferroelectrics, and Frequency Control, 2009

A coupled piezoelectric-circuit finite element model (CPC-FEM) is proposed for the first time to study the power output of a vibration-based piezoelectric vibration-based piezoelectric energy harvesting devices (EHDs) that is directly connected to a resistive load. Special focus is given to the effect of the resistive load value on the vibrational amplitude of the piezoelectric EHDs, and thus on the current, voltage, and power generated by the EHDs. In the literature, these outputs are widely assumed to be independent of the resistive load value for the reduction in complexity of modelling and simulation. The presented CPC-FEM uses a cantilever with sandwich structure and a seismic mass attached to the tip to study the following load characteristics of the EHD as a result of changing the resistive load value: (1) the electric outputs of the EHD: current through and voltage across the resistive load, (2) the power dissipated by the resistive load, (3) the vibration amplitude of tip displacement of the cantilever, and (4) the shift in resonant frequency of the cantilever. Investigation results shows significant dependences of the vibration characteristics of the piezoelectric EHDs on the externally connected resistive load are found, rather than independence as previously assumed in most literature. The CPC-FEM is capable of predicting the generated power output of the EHDs with different resistive load value while simultaneously calculating the effect of the resistive load value on the vibration amplitude. The CPC-FEM is invaluable for validating the performance