215 Evaluation of Energy Transfer Efficiency of Cantilever Type of Piezocomposite Vibration Energy Harvester

2012 ◽  
Vol 2012.11 (0) ◽  
pp. 140-145
Author(s):  
Kazuhiko ADACHI ◽  
Tatsuya SAKAMOTO
Keyword(s):  
Energy Transfer ◽  
Energy Harvester ◽  
Energy Transfer Efficiency ◽  
Transfer Efficiency ◽  
Vibration Energy ◽  
Vibration Energy Harvester

Theoretical and Experimental Evaluation of System Energy Balance and Power Generation Efficiency for Piezocomposite Vibration Energy Harvester Under Low Intensity Excitation Condition

2012 ◽  
Author(s):  
Kazuhiko Adachi ◽  
Tatsuya Sakamoto
Keyword(s):  
Energy Transfer ◽  
Energy Balance ◽  
Energy Harvester ◽  
Rotating Machinery ◽  
Energy Transfer Efficiency ◽  
Vibration Energy ◽  
Natural Period ◽  
Vibration Energy Harvester ◽  
Low Intensity ◽  
Ac Power

In the authors’ previous study, the vibration energy harvester of the piezoelectric bimorph cantilever type was proposed for vibration condition monitoring applications of industrial rotating machinery. According to an ISO standard, vibration level of newly commissioned class I rotating machinery is under 0.71mm/sec rms in all frequency range. Authors assumed that the typical casing or pedestal vibration amplitude of the rotating machinery was 0.71 mm/sec rms and this low intensity excitation condition was the input for experimental evaluation of the voltage generation performance of the piezocomposit vibration energy harvester. The vibration energy harvester consists of the surface bonded two Macro-Fiber Composites (MFCs). In this study, energy transfer efficiency was derived from the system energy balance during the natural period of the proposed vibration energy harvester. Energy balance equations were successfully obtained from the governing equations of the piezoelectrically coupled electromechanical system. The maximum AC power through 114.3 Kilo-Ohm resistor which includes instrument internal resistances experimentally obtained 242.07 microwatt when subjected to vibration source input magnitude of 0.71 mm/s rms at the resonant frequency of the harvester (29.42 Hz). The impedance matching between MFCs and the electrical resistive load was effective for maximizing AC power transfer of the vibration energy harvester. Estimated energy transfer from mechanical system to electrical system shows the agreement with the experimentally evaluated generating power during the natural period of the vibration energy harvester with about 3% difference. Estimated energy transfer efficiency was about 30% for different excitation magnitudes: 0.71, 0.568 and 0.355 mm/sec rms.

Simply supported FPEDs connected by springs for broadband energy harvesting

2020 ◽  
Vol 64 (1-4) ◽  
pp. 201-210
Author(s):  
Yoshikazu Tanaka ◽  
Satoru Odake ◽  
Jun Miyake ◽  
Hidemi Mutsuda ◽  
Atanas A. Popov ◽  
...  
Keyword(s):  
Energy Harvesting ◽  
Evaluation Method ◽  
Energy Harvester ◽  
Vibrational Energy ◽  
Functional Materials ◽  
Vibration Energy ◽  
Theoretical Evaluation ◽  
Vibration Energy Harvester ◽  
Polyvinylidene Difluoride ◽  
Simply Supported

Energy harvesting methods that use functional materials have attracted interest because they can take advantage of an abundant but underutilized energy source. Most vibration energy harvester designs operate most effectively around their resonant frequency. However, in practice, the frequency band for ambient vibrational energy is typically broad. The development of technologies for broadband energy harvesting is therefore desirable. The authors previously proposed an energy harvester, called a flexible piezoelectric device (FPED), that consists of a piezoelectric film (polyvinylidene difluoride) and a soft material, such as silicon rubber or polyethylene terephthalate. The authors also proposed a system based on FPEDs for broadband energy harvesting. The system consisted of cantilevered FPEDs, with each FPED connected via a spring. Simply supported FPEDs also have potential for broadband energy harvesting, and here, a theoretical evaluation method is proposed for such a system. Experiments are conducted to validate the derived model.

Hybrid Vibration Energy Harvester based on Stochastic Resonance

2018 ◽  
Vol 138 (5) ◽  
pp. 185-190
Author(s):  
Meng Su ◽  
Dai Kobayashi ◽  
Nobuyuki Takama ◽  
Beomjoon Kim
Keyword(s):  
Stochastic Resonance ◽  
Energy Harvester ◽  
Vibration Energy ◽  
Vibration Energy Harvester
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