Modeling Of Equivalent Series Resistance Of Super-capacitors

The super-capacitor has been widely used in many fields due to its excellent property as a new energy storage device.At present,the researches on the basic property of the super-capacitors have basically been ripe,for example,rated current,rated voltage and rated capacity,etc.However,the failure of the super-capacitors has always been the tremendous hidden danger in the use of the super-capacitors.Once one of the super-capacitor module fails,peripheral circuits devices and other connected super-capacitors suffer damages.So it has been the hotspot and focus of the current research which how to effectively predict the failure of the super-capacitor.The failure of the super-capacitor can be monitored by the equivalent series resistance(ESR)of the super-capacitor.There is a standard that it can be concluded that the super-capacitor failed when the equivalent series resistance of the super-capacitor changes more than 20% of the rated equivalent series resistance.Based on the above research purposes,the emphasis of this paper is to accurately measure the equivalent series resistance of the super-capacitor,and to monitor the change of the equivalent series resistance which is influenced by the external factors for judging failure problem.This article focuses on the following five aspects:1.on the basis of the internal structure and working principle of super-capacitors,the composition of the three-branch model of the super-capacitor is analyzed in an innovative way and summaries the composition and influence factors of equivalent series internal resistance;2.in the process of modeling of the equivalent series resistance,amend the part of the conductivity of the electrolyte based on the original formula,and the formula of the combined effect of ambient temperature and current on equivalent series internal resistance is derived;3.Accurate measure the equivalent series resistance of the super-capacitor accurately.Aimed at the problems in the dc test method,improve the testing procedures,and compare the equivalent series resistance which measured by the method which is improved before and after The results show that the improved test method is more accurate;4.design the control variable experiment to explore the influence of ambient temperature and charging current on the equivalent series resistance,and give the scientific explanation for some experimental results which do not conform to the formula;5.obtain the fitting method of the joint influence of the charging current and ambient temperature by fitting the experimental data,and realize the purpose of on-line monitoring the equivalent series resistance of the super-capacitor...