Design Of The Electric Vehicle’s Storage Battery Management System

Being the prime power resource, storage battery (SB) maintains its biggest shortage of insufficient energy storage capacity which confines the development of automobile industry. To solve this problem, apart from developing SB of bigger storage capacity, it’s also a key issue that the energy of SB is used to its fullest.In order to use the SB to its fullest, the latest researches are done in respects of the followings:1, strengthen the protecting. That is to say, SB should be steer clear of damage from all kinds of accidents;2, create a suitable working environment for SB;3, strengthen the balance degree of the series SB during the charging process, and find and replace the broken units among the group;4, precise prediction of the SB state of charge(SOC) not only helps the SB to charge and discharge more suitably, but also provides necessary data for the management of the electric vehicle’s whole energy. Combining these methods introduced above, the battery management system(BMS) is formed, all these functions are controlled by the VB software, which will finally accomplish the goals of improving the SB service efficiency, lengthening the SB life time, increasing the vehicle’s road haul, and so on.In order to fulfill the above functions, this paper designs a battery management control system which includes signal processing module, output driving module, industrial A/D capture card, I/O interface card, and an industrial computer. The signal processing module filters and amplifies the collected data of SB voltage, current, temperature and etc. and then input these data to A/D card. Computer collects these data and calculates to determine if it is necessary to accomplish relevant control and the SOC calculation. The output driving module controls the output of the signals of corresponding device. And now all these protection functions are fulfilled. As for the SOC calculation, in order to improve its estimation accuracy, we, with the Matlab-Simulink tool, build a full model of SB discharge which combines Kalman filtering method and ampere-hour integral method respectively with battery model to fulfill the simulation of SB’s SOC estimation. Meanwhile, we get the actual result by using the relation between the SB’s terminal voltage and SOC.As the experiment shows, the BMS of the design has basically accomplished the maximization use of the SB and ensured the SB’s safe and reliable operation. By comparison, we have found that the curve simulated by the Kalman filtering Matlab method is closer to the actual measuring result than that by ampere-hour method. Thus it’s testified that the Kalman filtering method has advantage over the traditional methods in respect of efficient and precise SOC estimation.