scholarly journals Investigation of the Dissipation Process in Electrolytic Capacitors

1980 ◽  
Vol 6 (2) ◽  
pp. 49-53
Author(s):  
Leconte Cathey ◽  
Keith A. Joyner
Keyword(s):  
Experimental Study ◽  
Thermal Properties ◽  
Power Dissipation ◽  
Series Resistance ◽  
Peak Voltage ◽  
Voltage Versus ◽  
Dissipation Process ◽  
Time Profiles ◽  
Electrolytic Capacitors ◽  
Charge Discharge

An experimental study of electrolytic capacitors was conducted, with emphasis on their thermal properties. The capacitors were subjected to charge–discharge cycles with various values of peak voltage. The observed power dissipated did not agree with that which would be expected if constant capacitance and constant effective series resistance (ESR) are assumed for the capacitors. In order to explain the discrepancy, the capacitance and ESR variations were measured with respect to voltage, temperature, and frequency. A predicted power dissipation was calculated for each capacitor; these dissipations compared favorably with those that were experimentally observed. In addition, voltage versus time profiles were measured for each unit and these were analyzed to determine the charge transport characteristics of the capacitors. The populations and mobilities of each type of charge carrier turned out to be quite similar from one capacitor sample to the next.

An experimental study on thermal properties of composite insulation

2007 ◽  
Vol 455 (1-2) ◽  
pp. 75-79 ◽  
Author(s):  
Gyoung-Seok Choi ◽  
Jae-Sik Kang ◽  
Young-Sun Jeong ◽  
Seung-Eon Lee ◽  
Jang-Yeul Sohn
Keyword(s):  
Experimental Study ◽  
Thermal Properties

Experimental Study on Thermal Properties of Hollow Sphere Structures

2021 ◽  
Vol 407 ◽  
pp. 185-191
Author(s):  
Josef Tomas ◽  
Andreas Öchsner ◽  
Markus Merkel
Keyword(s):  
Thermal Conductivity ◽  
Experimental Study ◽  
Thermal Properties ◽  
Thermal Diffusivity ◽  
Specific Heat ◽  
Hollow Sphere ◽  
Plane Source ◽  
Source Method ◽  
Transient Plane Source ◽  
Transient Plane Source Method

Experimental analyses are performed to determine thermal conductivity, thermal diffusivity and volumetric specific heat with transient plane source method on hollow sphere structures. Single-sided testing is used on different samples and different surfaces. Results dependency on the surface is observed.

scholarly journals How to Measure and Calculate Equivalent Series Resistance of Electric Double-Layer Capacitors

Molecules ◽  
2019 ◽  
Vol 24 (8) ◽  
pp. 1452 ◽  
Author(s):  
Rafael Vicentini ◽  
Leonardo Morais Da Silva ◽  
Edson Pedro Cecilio Junior ◽  
Thayane Almeida Alves ◽  
Willian Gonçalves Nunes ◽  
...  
Keyword(s):  
Double Layer ◽  
Electric Double Layer ◽  
Series Resistance ◽  
Voltage Drop ◽  
Equivalent Series Resistance ◽  
Galvanostatic Charge ◽  
Applied Current ◽  
Double Layer Capacitors ◽  
Charge Discharge ◽  
Electric Double Layer Capacitors

Electric double-layer capacitors (EDLCs) are energy storage devices that have attracted attention from the scientific community due to their high specific power storage capabilities. The standard method for determining the maximum power (Pmax) of these devices uses the relation Pmax = U2/4RESR, where U stands for the cell voltage and RESR for the equivalent series resistance. Despite the relevance of RESR, one can observe a lack of consensus in the literature regarding the determination of this parameter from the galvanostatic charge-discharge findings. In addition, a literature survey revealed that roughly half of the scientific papers have calculated the RESR values using the electrochemical impedance spectroscopy (EIS) technique, while the other half used the galvanostatic charge discharge (GCD) method. RESR values extracted from EIS at high frequencies (>10 kHz) do not depend on the particular equivalent circuit model. However, the conventional GCD method better resembles the real situation of the device operation, and thus its use is of paramount importance for practical purposes. In the latter case, the voltage drop (ΔU) verified at the charge-discharge transition for a given applied current (I) is used in conjunction with Ohm’s law to obtain the RESR (e.g., RESR = ΔU/ΔI). However, several papers have caused a great confusion in the literature considering only applied current (I). In order to shed light on this important subject, we report in this work a rational analysis regarding the GCD method in order to prove that to obtain reliable RESR values the voltage drop must be normalized by a factor of two (e.g., RESR = ΔU/2I).

scholarly journals Investigation of Electrochemical, Thermal and Electrical Performance of 3D Lithium-Ion Battery Module in a High -Temperature Environment

2020 ◽  
Vol 9 (2) ◽  
pp. 151-157
Author(s):  
Snigdha Sharma ◽  
Amrish Kumar Panwar ◽  
Madan Mohan Tripathi
Keyword(s):  
Thermal Properties ◽  
Lithium Ion Battery ◽  
Simulation Study ◽  
Lithium Ion ◽  
Open Circuit ◽  
Electrical Performance ◽  
Li Ion Battery ◽  
Peak Voltage ◽  
Simulation And Optimization ◽  
Li Ion

In the present time, the rechargeable lithium-ion battery is being commercialized to meet the sustained market’s demands. To design a more reliable, safe, and efficient Li-ion battery, a 3-D simulation study has been presented in this paper. In this study, a lithium-ion coin-cell is proposed which has LiFePO4 as a positive electrode with a thickness of 1.76 µm, carbon as a negative electrode with a thickness of 2.50 µm and Celgard 2400 polypropylene sheet as a separator between the electrodes with a thickness of 2 µm. The proposed Li-ion battery has been designed, analyzed, and optimized with the help of Multiphysics software. The simulation study has been performed to analyze the electrochemical properties such as cyclic voltammetry (CV) and impedance spectroscopy (EIS). Moreover, the electrical and thermal properties at the microscopic level are investigated and optimized in terms of surface potential distribution, the concentration of electrolyte, open circuit, and surface temperature with respect to time. It has been noticed that the peak voltage, 3.45 V is observed as the temperature distribution on the surface varies from 0 OC to 80 OC at a microscopic scale with different C-rates. The analysis of simulation results indicates a smoother electrode surface with uniform electrical and thermal properties distribution resulting in improved reliability of the battery. The performed simulation and optimization are helpful to achieve control over battery performance and safe usage without any degradation of the environment.©2020. CBIORE-IJRED. All rights reserved.

A comparative experimental study of the thermal properties of cricket helmets

2013 ◽  
Vol 43 (2) ◽  
pp. 161-169 ◽  
Author(s):  
Toh Yen Pang ◽  
Aleksandar Subic ◽  
Monir Takla
Keyword(s):  
Experimental Study ◽  
Thermal Properties

Experimental Study on a Gyromagnetic Piezo-Cantilever Generator

2013 ◽  
Vol 394 ◽  
pp. 416-420
Author(s):  
Yi Feng Chen ◽  
Jun Wu Kan ◽  
Shu Yun Wang ◽  
Fang Sheng Huang ◽  
Ping Zeng
Keyword(s):  
Experimental Study ◽  
Output Voltage ◽  
Magnetic Force ◽  
Energy Generation ◽  
Peak Voltage ◽  
Research Results ◽  
Rotating Speed ◽  
Speed Range ◽  
Rotating Structure

To meet the demands of the rotating structure for self-power, a novel gyromagnetic piezo-cantilever generator (GPCG) excited by the coupling between rotating magnets and those fixed on piezo-cantilever was presented. The influence of magnetic force (number and configuration of the magnets) and rotating speed on energy generation of the GPCG was investigated experimentally. The research results show that there are 9 optimal rotating speeds for the GPCG to achieve peak voltage at speed range of 0-1390r/min. With 1 magnet (ø12x2mm3) fixed on piezo-cantilever, the increasing number of rotating magnets (ø12x4mm3) in the same place (ns) of the rotator exerts no influence on the optimal rotating speeds, but leads to rising output voltage. At 1042.5r/min, the achieved peak voltages from the GPCG in the case ofns=1/2/4/6 are 13.2/16.6/23.8/27.8V respectively. The optimal speeds decrease and the peak voltage rises with the increasing number of magnets evenly distributed on the rotator (nd). In the case of 1 magnet fixed on piezo-cantilever andnd=1/2/4/8, the optimal rotating speeds and the peek voltages from the GPCG are 708.9/528.2/528.2/264.1r/min and 13.2/16.6/23.8/27.8V respectively.

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