Maximum Energy-Efficiency Compliant Mechanism Design for Piezoelectric Stack Actuators

Aerospace ◽  
2003 ◽  
Author(s):  
Mostafa M. Abdalla ◽  
Mary Frecker ◽  
Zafer Gu¨rdal ◽  
Terrence Johnson ◽  
Douglas K. Lindner

Combined optimization of a compliant mechanism and a piezoelectric stack actuator for maximum energy conversion efficiency is considered. The paper presents a system level analysis in which the actuator and the compliant mechanism are mathematically described as linear two-port systems. The combination of stack and compliant mechanism is used to drive a structure, modeled as a mass-spring system. The analysis assumes all components to be free from dissipation, and the piezoelectric stack is driven by an ideal voltage source. Energy conversion efficiency is defined as the ratio of the output mechanical energy to the input electric energy. Theoretical bounds on the system efficiency are obtained. It is shown that the stack actuator can be optimized separately and matched to the specified structure and an optimally designed complaint mechanism. The optimization problem for the compliant mechanism is formulated to maximize a weighted objective function of energy efficiency and stroke amplification. Optimization results are presented for ground structures modeled using frame elements.

2018 ◽  
Vol 192 ◽  
pp. 01032
Author(s):  
Zhen-Qiang Song ◽  
Sriyuttakrai Sathin ◽  
Wei Li ◽  
Kazuhiro Ohyama ◽  
ShiJie Zhu

The dielectric elastomer generator (VHB 4905, 3M) with diaphragm configuration was investigated with the constant-voltage harvesting scheme in order to investigate its energy harvesting ability. The maximum energy density and energy conversion efficiency is measured to be 65 J/kg and 5.7%, respectively. The relatively low efficiency indicates that higher energy conversion efficiency is impeded by the viscosity of the acrylic elastomer, suggesting that higher conversion efficiency with new low-viscosity elastomer should be available.


2021 ◽  
pp. 1-23
Author(s):  
Dandan Pang ◽  
Aibing Zhang ◽  
Zhenfei Wen ◽  
Baolin Wang ◽  
Ji Wang

Abstract Thermoelectric power generators (TEGs) have been attracted increasing attention recently due to their capability of converting waste heat into useful electric energy without hazardous emissions. This paper develops a theoretical model to analyze the thermoelectric performance of TEGs with cylindrical legs. The influence of heat convection loss between lateral surfaces of thermoelectric legs and ambient environment on the energy conversion efficiency is investigated. For the idealized model, closed-form solutions of optimal electric current, maximum power output and maximum energy conversion efficiency are obtained, a new dimensionless impact factor H is introduced to capture the heat convection effect. The impact factor H depends on the ratio of heat conductivity to heat convection coefficient and geometry size of thermoelectric legs, as well as the temperature ratio of heat sink to hot source. The performance can be evaluated by the figure of merit, impact factor H and temperature gradient across the hot source and heat sink for a well-designed TEG with cylindrical legs. For the case of considering contact resistance, it is found that there exists an optimal leg's height for maximum energy conversion efficiency due to the heat convection on lateral surfaces of thermoelectric leg. The proposed theoretical model in this paper will be very helpful in the designing of actual TEG devices.


2021 ◽  
Vol 926 (1) ◽  
pp. 012091
Author(s):  
W Rahmalia ◽  
E Crespo ◽  
T Usman

Abstract Dye-sensitized solar cell (DSSC) is a third-generation solar cell that has been developed as one of the clean and renewable alternative energies. This study aims to fabricate norbixin-sensitized solar cell (NSSC). Norbixin was obtained from the saponification followed by acidification of bixin and characterized using UV-Visible and FTIR spectroscopy. The solar cell was assembled using anatase-TiO2 semiconductor, KI/I2/MPII in acetonitrile as the electrolyte, and a platinum paste-based cathode. The UV-Visible spectrophotometry analysis results showed three peaks of carotenoid characteristics at 434, 457, and 486 nm. The formation of norbixin was proved by the absence of a spectral peak for the C-O-C ester group of bixin at 1254 dan 1159 cm-1” The cells performance test showed that the maximum energy conversion efficiency of NSSC increased with increasing light intensity up to 0.08 W/cm2. Exposure to the light above this intensity causes a decrease in the maximum energy conversion efficiency due to the temperature factor. The data also showed that the cell assembled was reusable. It still showed relatively good performance until the third day of analysis.


2015 ◽  
Vol 51 (29) ◽  
pp. 6315-6317 ◽  
Author(s):  
Kenji Kakiage ◽  
Yohei Aoyama ◽  
Toru Yano ◽  
Keiji Oya ◽  
Toru Kyomen ◽  
...  

A dye-sensitized solar cell co-photosensitized with metal-free organic silyl-anchor dyes exhibited a high light-to-electric energy conversion efficiency of 12.8% under one sun conditions.


Author(s):  
Jasim Uddin ◽  
Jahid M.M. Islam ◽  
Shauk M.M. Khan ◽  
Enamul Hoque ◽  
Mubarak A. Khan

Dye sensitized solar cell (DSSC) shows great promise as an alternative to conventional p-n junction solar cells due to their low fabrication cost and reasonably high efficiency. DSSC was assembled by using natural dye extracted from red amaranth (Amaranthus Gangeticus) as a sensitizer and different catalysts for counter electrode were applied for maximum energy conversion efficiency. Annealing temperature and thickness of electrode were also investigated and optimized. Catalyst, annealing temperature and thickness were optimized by the determination of cell performance considering photoelectrochemical output and measuring current and voltage; then calculating efficiency and other electrical parameters. The experimental results indicated that samples having 40 µm electrode thickness and prepared at 450 °C annealing temperature showed the best performance


Author(s):  
Sukrisno Widyotomo ◽  
Sri Mulato ◽  
Hadi K. Purwadaria ◽  
A.M Syarief

AbstractThis experiment aims to know the solar energy efficiency of four clones of cocoa that cultivated under three different shading plants. This experiment has been done from September until December 2013 located at Kaliwining Experiment Farm with characteristic 45 m above sea level, soil type is low humic gley, soil texture is silty clay loam, and climate classification type D based on Scmidht and Fergusson Classification. This experiment used Nested Design as Experimental Design with species of shading plant as main plot which are Teak (Tectona grandis L.), Krete (Cassia surattensis (Burm.) F.), Lamtoro (Leucaena leucocephala L.) and Cocoa clones as sub plot which are Sulawesi 1, Sulawesi 2, KKM 22, KW 165. The observation of solar energy efficiency consists of daily solar radiation intensity, solar radiation intensity above plant, solar radiation intensity under plant, and also plant total dry weight. The experimental result showed that there is differences (heterogenity) between shading location based on homogenity test by Bartlett Method. There are some interaction between the kind of shading plant and clones in parameter of interception efficiency, absorbtion efficiency, the efficiency of solar energy that caught by plant, and solar energy conversion efficiency. The efficiency of solar energy that caught by plant will affect the solar energy conversion efficiency with R2 = 0,86.  Keywords : Solar Energy Efficiency, Cocoa Clones, Shading Plant, Nested Design, Bartlett Method


Author(s):  
Adel Younis ◽  
Leon Zhou ◽  
Zuomin Dong

Electric Vehicles (EV), Hybrid Electric Vehicles (HEV), Plug-in Hybrid Electric Vehicles (PHEV) and Extend Range Electric Vehicles (EREV) draw mechanical power or regenerate electric power using multiple electric motors and generators (M/Gs). Conventionally, heuristics and experience based control rules are used to guide the determination of powertrain component operation parameters to obtain good efficiency. To achieve optimal vehicles electrical/mechanical energy conversion efficiency and to prolong the pure electric range of these vehicles, the energy conversion efficiency is to be maximized against powertrain component operation parameters using high fidelity model and simulation. However, the energy conversion efficiency model using vehicle powertrain component model and simulation is complex, multimodal, and computationally intensive. An efficient global optimization tool is needed to produce the optimal efficiency look-up surface for real-time control system implementation, or to search for the optimal operation parameters in real time. In this work, the electrical/mechanical energy conversion efficiency of EV and PHEV/EREV in EV mode is modeled using MATLAB Simulink based powertrain component models. In particular, a new 2 mode-plus EREV design is used as a design example. The optimal vehicle electrical/mechanical energy conversion efficiency under various powertrain component operation parameters are obtained using three alternative global optimization tools, Genetic algorithm (GA), Particle Swarm Optimization (PSO) and Space Exploration and Unimodal Region Elimination (SEUMRE). The conventional GA and PSO tools, with less efficient search efficiency and requiring long search time, are used for benchmark comparisons. The new SEUMRE global optimization tool is used obtain equally accurate results much efficiently. A rough look-up surface is created to demonstrate the difference in computational efficiency. Application of the SEUMRE global optimization tool allow refined and more accurate vehicle electrical/mechanical energy conversion efficiency map being created for the optimal operation of the EV/PHEV/EREV Optimal vehicle control schemes can then be generated in determining the speed and torque of the M/Gs of the vehicle without violating their physical constraints and achieving the overall maximum efficiency of the hybrid powertrain system. Results of the design optimization are presented and compared. New design guidelines are provided.


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