Determination of Regression Functions for the Charging and Discharging Processes of Valve Regulated Lead-Acid Batteries
Abstract
Abstract: Following the deep discharge of the valve-regulated lead-acid batteries of the type AGM SVT 300, using the ten-hour-discharge current, charging of the batteries with the variable current was performed. In accordance with the obtained results, exponential and polynomial functions for approximation of the specified processes were analyzed. The main evaluation instrument for a quality of the implemented approximations was the adjusted coefficient of determination, R^2. It was perceived that the battery discharge process may be successfully approximated both with exponential and the second order polynomial function. On all the analyzed occasions values of the adjusted coefficient of determination were greater than 0.995. Charging process of the deeply discharged battery was successfully approximated with the exponential function, with the measured values of the adjusted coefficient of determination being nearly 0.95. Beside the high measured values of the adjusted coefficient of determination, polynomial approximations of the second and third order did not provide satisfactory results regarding the interpolation of the battery charging characteristics. A possibility for a practical implementation of the procured regression functions in uninterruptible power supply systems was described.
References
D. Doerfell, S. Abu Sharkh, A critical review of using the Peukert equation for determining the remaining capacity of lead-acid and lithium-ion batteries, Journal of Power Sources, vol. 155, pp. 395-400, 2006.
N.A. Chaturvedi, R. Klein, J. Christensen, J. Ahmed, A. Kojić, Algorithms for advanced battery-management systems - Modeling, estimation and control challenges for lithium-ion batteries, IEEE Control Systems Magazine, vol. 30, no. 3, pp. 49-68, 2010.
Y.H. Sun, H.L. Jou, J.C. Wu, Aging estimation method for lead-acid battery, IEEE Transactions on Energy Conversion, vol. 26, no. 1, pp. 264-271, 2011.
V. Vukić, R. Prole, D. Jevtić, Novo postrojenje sa tiristorskim ispravljačima i razvodom jednosmerne struje za napajanje hidroelektrane, Zbornik radova, Elektrotehnički institut „Nikola Tesla”, Knjiga 20, str. 143-156, 2010.
SVT SGM VRLA Batteries, Germanos Sunlight S.A., 2006.
IEEE Recommended Practice for Maintenance, Testing, and Replacement of Valve-Regulated Lead-Acid (VRLA) Batteries for Stationary Applications, IEEE Std 1188-1996, 20th June 1996.
287/289 True-rms Digital Multimeters, Calibration Manual, Fluke Corporation, 2009.
B.S. Everitt, The Cambridge Dictionary of Statistics, Cambridge University Press, Cambridge, United Kingdom, 2002.
H.Theil, Economic Forecasts and Policy, North, Amsterdam, Holland, 1961.
V. Vukić, Tiristorski ispravljači sa digitalnim regulatorima zasnovanim na mikrokontroleru 80S196 za sisteme besprekidnog napajanja, Zbornik radova, Elektrotehnički institut „Nikola Tesla”, Knjiga 21, str. 139-155, 2011.
V. Vukić, Energetska efikasnost i digitalna komunikacija fazno regulisanih ispravljača za industrijske sisteme besprekidnog napajanja, Poljoprivredna tehnika, Godina XXXVI, br. 3, str. 19-28, 2011.
V. Vukić, Tiristorski ispravljač upravljan programabilnim logičkim kontrolerom sa modularnim čoperskim izlaznim stepenom, Zbornik radova, Elektrotehnički institut „Nikola Tesla”, Knjiga 19, str. 85-92, 2008.-2009.
R.C. Cope, Y. Podrazhansky, The art of battery charging, The 14th Annual Battery Conference on Applications and Advances, pp. 233-235, 1999.