The Research And Design Of Equilibrium In Power Batteries

With the sustained and rapid development of economy, the number of car ownership of every country in the world is growing at a rapid rate. But for the short of oil, traditional cars are being replaced by the electric automobile. As the main power source, vehicle batteries are largely used and accepted by people because its green effect.Nowadays, limited by the technology of battery manufacture, batteries are still connected in series in order to give enough power. In fact, the characters of batteries in the same series package will go different as used-time past, this causes a relatively low use ratio of energe and short cycle life. This presented problem becomes even essential when the batteries used in series are types of lithium, which is rather expensive, because low use ratio and short cycle life means unnecessary economic losses. In order to solve this problem, a certain circuit used to equalize the state of charge among batteries is studied, which makes sense not for the application of batteries in series used but also used in other fields.This paper mainly covers the following points about the research and design of equilibrium in power batteries.1,Compare the existed equilizing circuits in two different points of view, which are circuit structure and control strategy.2,Study the voltage and current features of vehicle batteries.3,Analyse the principle of the equilizing circuit presented by this paper, also give design details.4,First Based on the dynamics feature of vehicle batteries, a general-used SOC estimating method is proposed. Second, study the control strategy by Matlab Simulink Tools. Finally, the batteries in series are equalized by the equalizing circuit under certain test conditions.5,Make a conclusion of all the study above and look forward to the further development in this research field.