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Farvagny le Petit, Switzerland

Gualous H.,University of Caen Lower Normandy | Louahlia H.,University of Caen Lower Normandy | Gallay R.,Garmanage
IEEE Transactions on Power Electronics | Year: 2011

This paper investigates double layer capacitor (or supercapacitor) thermal modelling. The originality of this work resides in the fact that 4 type K thermocouples are inserted inside a 350 F supercapacitor modified cell. These thermocouples allow supercapacitor internal temperature measurement. Experimental results have shown that the electrical storage device temperature increases in the phase of charge and decreases during the discharge. The developed model takes into account the effect which is due to the reversible heat generation in the supercapacitor. The model is based on heat equation solution and allows temperature distribution determination inside and outside the supercapacitor as a function of the position and of the time. The model is developed for double layer capacitor based on activated carbon and organic electrolyte technology. © 2011 IEEE. Source


Voicu I.,University of Caen Lower Normandy | Louahlia H.,University of Caen Lower Normandy | Gualous H.,University of Caen Lower Normandy | Gallay R.,Garmanage
Applied Thermal Engineering | Year: 2015

The main objective of this study is to investigate heat transfer inside and around a supercapacitor stack. The crossflow staggered arrangement with five rows was also studied for different transverse and longitudinal pitches. The mathematical model governing the problem is numerically solved in a three-dimensional computational domain using the commercial computational fluid dynamic package Fluent 6.3. The model is elliptic and takes into account orthotropic thermal conductivity in the active zone. The average Nusselt number and friction factor results of the present model are in good agreement with previously published experimental data of different authors for flow across tube banks. The results include evolution of the maximum temperature of each supercapacitor and contours of temperature distribution. For a definite ventilation power, the arrangement with the lowest spacing provides maximum cooling performance. Inside the supercapacitor the temperature distribution is not concentric around the axis and the maximum temperature is downstream. In the axial direction the temperature variation can be neglected. © 2015 Elsevier Ltd. All rights reserved. Source


Gualous H.,University of Caen Lower Normandy | Camara M.B.,University of Le Havre | Boudrat B.,University of Caen Lower Normandy | Gallay R.,Garmanage | Dakyo B.,University of Le Havre
International Conference on Power Engineering, Energy and Electrical Drives | Year: 2013

This study deals with the dynamic and thermal behaviors of supercapacitors. Characterization is performed using the Electrochemical Impedance Spectroscopy (EIS) method to determine by experiment the supercapacitor's series resistance (ESR) and capacitance according to the frequency. The study deals also the particular case of the supercapacitor's spectra and the thermal shock. Finally, life test at constant temperature and the impact of the vibration on the supercapacitor's parameters are illustrated. © 2013 IEEE. Source


Gualous H.,University of Caen Lower Normandy | Gallay R.,Garmanage | Alcicek G.,University of Caen Lower Normandy | Tala-Ighil B.,University of Caen Lower Normandy | And 3 more authors.
Microelectronics Reliability | Year: 2010

This paper presents supercapacitor ageing according to the voltage, the temperature and thermal shock tests. To investigate this effect, a test bench of accelerated supercapacitor calendar ageing was carried out. Experimental tests are realized at constant temperature when the supercapacitors are polarized at the maximum voltage. To quantify the supercapacitor ageing, the equivalent series resistance (ESR) and the equivalent capacitance (C) are measured using the DC and AC characterization. To lead to the determination of the supercapacitor lifetime, Arrhenius law, that describes the effect of temperature on the velocity of a chemical reaction, is considered. Finally, experimental results of supercapacitor thermal shock are presented. © 2010 Elsevier Ltd. All rights reserved. Source


Oukaour A.,University of Caen Lower Normandy | Tala-Ighil B.,University of Caen Lower Normandy | Alsakka M.,Vrije Universiteit Brussel | Gualous H.,University of Caen Lower Normandy | And 2 more authors.
Electric Power Systems Research | Year: 2013

A new method of supercapacitor online health diagnosis based on an electric model and on experimental results obtained by calendar ageing tests is proposed. The calendar ageing of supercapacitor is mainly related to thermal and voltage constraints from the application. This ageing causes the degradation of supercapacitor performances which can finally lead to failures. In vehicle applications, the goal is to avoid these failures which may have serious consequences and high non-quality costs. The device survey and ageing state detection are a priority for anticipating the problems. This paper presents the case of calendar ageing tests on supercapacitors made of activated carbon and organic electrolyte. The ageing is performed at constant temperature (65 °C) under a 2.9 Vdc bias voltage. These tests permit to highlight online and in real-time the measurable external indicators of ageing. © 2012 Elsevier B.V. All rights reserved. Source

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