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Research Status of Wind Energy Piezoelectric Generator  [PDF]
Chunhua Sun, Guangqing Shang
Energy and Power Engineering (EPE) , 2018, DOI: 10.4236/epe.2018.1012031
Abstract: It is of great significance for developing self-powered micro-devices to explore the research of piezoelectric effect in conversion of wind energy into electricity. Based on the different excitation modes, the existing wind energy piezoelectric generators are firstly classified. The research status of wind piezoelectric generators is further analyzed, and characteristics of various types of wind energy piezoelectric generators are summarized. Finally, the future research direction and emphasis of wind energy piezoelectric generators is proposed to carry out its miniaturization, lightweight and integration.
Multi-Direction Piezoelectric Energy Harvesting Techniques  [PDF]
Chunhua Sun, Guangqing Shang
Journal of Power and Energy Engineering (JPEE) , 2019, DOI: 10.4236/jpee.2019.79003
Abstract: With the development of portable and self-powering electronic devices, micro-electromechanical system (MEMS) and wireless sensor networks, research on piezoelectric energy harvesting techniques has been paid more and more attention. To enhance the ambient adaptability and improve the generating efficiency, the multi-directional piezoelectric energy harvesting techniques turns to be a research hotspot. The current status of the multi-directional piezoelectric energy harvesting techniques was firstly reviewed. The characteristics of existed multi-directional piezoelectric harvester were then analyzed. An improved structure of multi-directional piezoelectric harvester was finally proposed. The multi-directional piezoelectric energy harvester has a good prospect in miniaturization, more sensitive to vibration directions and better energy efficiency.
Piezoelectric Power Harvesting via Acoustic-Pressure Driven by Low-Speed Wind-Force with Resonating-Tube and Wind-Collector  [PDF]
Seiichi Deguchi, Hiroya Taguchi, Hajime Arimura, Noriyuki Kobayashi, Norifumi Isu, Kentaro Takagi, Tsuyoshi Inoue, Takashi Nozoe, Seigo Saito, Takahiko Sano
Journal of Power and Energy Engineering (JPEE) , 2018, DOI: 10.4236/jpee.2018.611005
Abstract: Wind-driven power harvestings attract attentions since their target wind speeds are quite low less than the so-called cut-in wind speed, which is generally recognized as around 3 m/s. The extant power harvestings driven by wind-induced-air-column-resonations (i.e. acoustic-pressures) are still lacking simplicity, scale flexibility and solid strategies for practical applications. Therefore, the piezoelectric power harvesters via acoustic-pressures driven by low-speedwind-forces with resonating-tubes and wind-collectors were invented so as to complement all the lacks. The wind-collector as well as the resonating-tube contributed to upraise the power harvesting density. The champion power harvesting density of 19.5 nW/dm2 could be procured at 2.3 m/s of an artificial wind and the optimal resonating-tube and wind-collector. Power harvesting proofs from the natural wind with low mean speeds down to about 0.6 m/s were successfully obtained. The cut-in wind speed of the prototype piezoelectric power harvester was found to be quite low as about 0.4 m/s, signifying its ubiquity. Finally, a multi-bundle pendant-type piezoelectric power harvester was specifically presented together with professing the solid and multiple strategies for practical applications.
Energy Harvesting Strategy Using Piezoelectric Element Driven by Vibration Method  [PDF]
Dong-Gun Kim, So-Nam Yun, Young-Bog Ham, Jung-Ho Park
Wireless Sensor Network (WSN) , 2010, DOI: 10.4236/wsn.2010.22014
Abstract: This study demonstrates a method for harvesting the electrical power by the piezoelectric actuator from vibration energy. This paper presents the energy harvesting technique using the piezoelectric element of a bimorph type driven by a geared motor and a vibrator. The geared motor is a type of PWM controlled device that is a combination of an oval shape cam with five gears and a speed controller. When using the geared motor, the piezoelectric element is size of 36L×13W×0.6H. The output voltage characteristics of the piezoelectric element were investigated in terms of the displacement and vibration. When using the vibrator, the electric power harvesting is based on piezoelectric effect and piezoelectric vibrator consists of a magnetic type oscillator, a cantilever, a bimorph actuator and controllers. Low frequency operating technique using piezoelectric vibrator is very important because normal vibration sources in the environment such as building, human body, windmill and ship have low frequency characteristics. We can know from this study results that there are many energy sources such as vibration, wind power and wave power. Also, these can be used to the energy harvesting system using smart device like piezoelectric element.
Piezoelectric Energy Harvesting Devices: An Alternative Energy Source for Wireless Sensors  [PDF]
Action Nechibvute,Albert Chawanda,Pearson Luhanga
Smart Materials Research , 2012, DOI: 10.1155/2012/853481
Abstract: The recent advances in ultralow power device integration, communication electronics, and microelectromechanical systems (MEMS) technology have fuelled the emerging technology of wireless sensor networks (WSNs). The spatial distributed nature of WSNs often requires that batteries power the individual sensor nodes. One of the major limitations on performance and lifetime of WSNs is the limited capacity of these finite power sources, which must be manually replaced when they are depleted. Moreover, the embedded nature of some of the sensors and hazardous sensing environment make battery replacement very difficult and costly. The process of harnessing and converting ambient energy sources into usable electrical energy is called energy harvesting. Energy harvesting raises the possibility of self-powered systems which are ubiquitous and truly autonomous, and without human intervention for energy replenishment. Among the ambient energy sources such as solar energy, heat, and wind, mechanical vibrations are an attractive ambient source mainly because they are widely available and are ideal for the use of piezoelectric materials, which have the ability to convert mechanical strain energy into electrical energy. This paper presents a concise review of piezoelectric microgenerators and nanogenerators as a renewable energy resource to power wireless sensors. 1. Introduction The advances in low power electronics, and wireless sensor networks (WSNs) in particular, have driven numerous researches in the field of energy harvesting in the past decade [1–3]. A wireless sensor node consists of low power microcontroller unit, radio frequency transceiver and microelectromechanical- (MEMS-) based sensor. The task of each node is to collect and transmit data to the outside world via a radio link. Thousands of spatially distributed wireless sensors can be developed which can be embedded virtually anywhere in civil structures, bridges, or in the human body. WSN technology has gained increasing importance in industrial automation [4, 5], structural health monitoring [6], healthcare [7], agriculture [8], and civil and military applications [9–11]. Traditionally, batteries are used as the electrical energy power sources to power wireless sensors and embedded electronics. However, batteries have a limited life span and they are expensive to maintain and hence they are not a long-term viable source of energy for WSNs and embedded systems. In fact, the limited capacity of batteries is one of the main factors constraining the performance and limiting the lifespan of a typical WSN [2,
Energy harvesting efficiency of piezoelectric flags in axial flows  [PDF]
Sebastien Michelin,Olivier Doare
Physics , 2012, DOI: 10.1017/jfm.2012.494
Abstract: Self-sustained oscillations resulting from fluid-solid instabilities, such as the flutter of a flexible flag in axial flow, can be used to harvest energy if one is able to convert the solid energy into electricity. Here, this is achieved using piezoelectric patches attached to the surface of the flag that convert the solid deformation into an electric current powering purely resistive output circuits. Nonlinear numerical simulations in the slender-body limit, based on an explicit description of the coupling between the fluid-solid and electric systems, are used to determine the harvesting efficiency of the system, namely the fraction of the flow kinetic energy flux effectively used to power the output circuit, and its evolution with the system's parameters. The role of the tuning between the characteristic frequencies of the fluid-solid and electric systems is emphasized, as well as the critical impact of the piezoelectric coupling intensity. High fluid loading, classically associated with destabilization by damping, leads to greater energy harvesting, but with a weaker robustness to flow velocity fluctuations due to the sensitivity of the flapping mode selection. This suggests that a control of this mode selection by a careful design of the output circuit could provide some opportunities of improvement for the efficiency and robustness of the energy harvesting process.
On Piezoelectric Energy Harvesting from Human Motion  [PDF]
Chunhua Sun, Guangqing Shang, Hongbing Wang
Journal of Power and Energy Engineering (JPEE) , 2019, DOI: 10.4236/jpee.2019.71008
Abstract: With the rapid development of low-power communication technology and microelectronics technology, wearable and portable embedded health monitoring devices, micro-sensors, and human body network positioning devices have begun to appear. For seeking reliable energy sources to replace battery on these devices, it is of great significance for developing low power products to explore the research of piezoelectric effect in conversion of human motion into electricity. Based on the different human motions, the existing technology of piezoelectric energy harvester (PEH) is firstly classified, including PEHs through heel-strike, knee-joint, arm motion, center of mass. The technology is then summarized and the direction of future development and efforts is further pointed out.
Influence and optimization of the electrodes position in a piezoelectric energy harvesting flag  [PDF]
Miguel Pi?eirua,Olivier Doaré,Sébastien Michelin
Physics , 2015, DOI: 10.1016/j.jsv.2015.01.010
Abstract: Fluttering piezoelectric plates may harvest energy from a fluid flow by converting the plate's mechanical deformation into electric energy in an output circuit. This work focuses on the influence of the arrangement of the piezoelectric electrodes along the plate's surface on the energy harvesting efficiency of the system, using a combination of experiments and numerical simulations. A weakly non-linear model of a plate in axial flow, equipped with a discrete number of piezoelectric patches is derived and confronted to experimental results. Numerical simulations are then used to optimize the position and dimensions of the piezoelectric electrodes. These optimal configurations can be understood physically in the limit of small and large electromechanical coupling.
On the characteristics of ASCAT wind direction ambiguities  [PDF]
W. Lin,M. Portabella,A. Stoffelen,A. Verhoef
Atmospheric Measurement Techniques Discussions , 2012, DOI: 10.5194/amtd-5-8839-2012
Abstract: The inversion of the Advanced Scatterometer (ASCAT) backscatter measurement triplets generally leads to two wind ambiguities with similar wind speed values and opposite wind directions. However, for up-, down- and cross-wind (with respect to the mid beam azimuth direction) cases, the inversion often leads to three or four wind solutions. In most of such cases, the inversion residual or maximum likelihood estimator (MLE) of the 3rd and 4th solutions (i.e. high-rank solutions) are substantially higher than those of the first two (low rank) ambiguities, indicating a low probability of the former and thus essentially dual ambiguity. This paper investigates the characteristics of ASCAT high-rank wind solutions under different conditions with the objective to develop a method for rejecting the spurious high-rank solutions. The implementation of this rejection procedure improves the effectiveness of the ASCAT wind quality control (QC) and ambiguity removal procedures.
Improved Performance of the Piezoelectric Monomorph with Perpendicular Electrode Connections for Sensing and Energy Harvesting  [PDF]
Ming Ma,Zhenrong Li,Xiaoyong Wei,Zhuo Xu,Xi Yao
Smart Materials Research , 2013, DOI: 10.1155/2013/957460
Abstract: Piezoelectric monomorph, which has only one element, is a potential structure for piezoelectric applications in some extreme conditions. But as the restriction of the strain neutral layer, the traditional parallel electrode connection is not effective for sensing and energy harvesting. In this paper, perpendicular electrode connections were designed to utilize the nonuniform shear piezoelectric effect in the cross section of the monomorph, which made the monomorph avoid the restriction of the strain neutral layer. The PZT5 ceramic monomorph was preliminarily studied in this experiment. By comparing seven forms of perpendicular electrode connections with the traditional parallel electrode connection, the whole superposed perpendicular electrode connection is considered as the optimal output way for the monomorph. It can produce 13?V peak-to-peak (pk-pk) voltage in open circuit and 14.56?μW maximum power with the matching resistance, which are much more than the parallel electrode connection 0.78?V and 0.14?μW. 1. Introduction Piezoelectric cantilever is widely used in the piezoelectric device for sensing and energy harvesting [1–6]. At room temperature and ambient pressure, unimorph and bimorph, which utilize the lateral extensional piezoelectric effect, are considered as a promising solution for sensing and energy harvesting [7, 8]. But when both of the above composite structures are used under the relative tough environment, such as high temperature and high pressure or low temperature and low pressure, the stability and performance of the device will be lower as the thermal-oxidative degradation and the low temperature brittleness of the bonding materials between different components. Even in the normal situation, the internal stresses and the permanent strain in the bonding layer will lead to the rapid deterioration of the device after long time using [9]. As for the simplest transducer that has only one piezoelectric component, the piezoelectric monomorph avoids the bonding issues and is considered as the only solution in the extreme conditions. But the existence of the strain neutral layer, which is in the middle of the thickness of the piezoelectric element, neutralizes the positive and negative induced charges [10]. As a result, with the traditional parallel electrode connection, the monomorph is not effective in the piezoelectric applications. In order to improve the performance of the monomorph, many studies have been focused on the nonuniform polarization inside the piezoelectric materials. Based on the nonuniform distribution of the electric
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