Design And Research Of Equalization System For Dynamic Lithium-Ion Battery

Single batteries connected with the form of series & parallel integration within the battery pack in pure battery vehicle. However, due to the limitation of the manufacture craft and abnormal use of the lithium-ion battery, each battery has different features. These features will case overcharge or over-discharge, make the batteries in series charge and discharge inconsistently, which may reduce the capacity of the battery pack.In this paper, based on the project of The Research of Intelligent and Efficient Power Battery Management System, A equalization system has been designed and has been verified too. The main work that have done can be listed as follows:Charging and discharging same single LiFePO4 battery repeatedly to calculate the characteristic curve. Based on this experiment, another experiment has been done to verify the temperature influence on battery charge and discharge period. By the same steps, the characteristic curve has been calculated.According to the characters of the main control chip, hardware circuit of communication, power support, balance, isolation, protection have been designed. And, corresponding software program have been designed to satisfy the designed hardware circuit.In the proposed equalization system, series-connected battery string is modularized into X modules. Each module contains a voltage monitoring IC and 6 single batteries. In this paper, two balance architecture have been designed to satisfy the requirement of the whole design scheme. And then, build the model of LiFePO4 battery, energy transform circuit and the balance circuit in Simulink.A printed circuit board has been made based on the designed scheme. Then, debugged the corresponding soft program. Both the simulation and experiment results are presented to validate the designed system.