Research On The Quick-Charging Technology For Lead-Acid Battery In EV Application

Electric vehicle (EV) with power batteries as on-board energy is considered as green transportation for the 21st century. But the development of lead-acid battery and relevant chargers cannot meet the EV's requirement, and some problems such as theory and technical matters need to be resolved further. Constrained to technologies, the lead-acid battery mainly adopted traditional charging methods such as constant voltage, constant voltage with current limitation, constant current, etc. The charging current of these methods cannot match efficiently the acceptance curve of the lead-acid battery proposed by J.A.MAS. As a result, some of these methods have a low time efficiency and incompleteness charging. And some of them lead to overcharge and gas-generation, which will result in low-efficiency, time-consuming and prone-to-damage of the charging operation. Therefore, the new research of technique that elevates the efficiency, shortens the time, and prolongs the battery life, has a very significant meaning.This thesis mainly proposed the research on fast-charging method of lead-acid battery. Based on knowledge of the electrochemistry mechanism of lead-acid battery, study on the fast-charging principle of depolarization with positive pulses alternated with negative pulses has been done with the J. A. MAS's law. Many experiments on the effects with the change of several parameters, such as initial charging current, amplitude and frequency of positive pulses, variety of the amplitude of positive pulses among each charging stages, amplitude and duration of negative pulses, duration between positive and negative pulses, have been performed. The results of analysis and comparison of experimental data verify the validity and feasibility of the fast-charging method. On this basis, a new type of control strategy is advanced. In this thesis, experimental results and charging waveforms of this strategy are shown and discussed, which can be a reference and foundation for the design of fast-charger for EV.The experiment results indicates that the application of the novel method with fast-charging control strategy can increase the charging efficiency and shorten the charging time, and there was no apparent rise of electrolyte...