Fast charge circuit for lithium battery based on DSP control

YANG Yanyong, WANG Tengfei, WANG Huixin, YANG Lei, WANG Zhengshi

(College of Electrical Engineering, Zhejiang University, Hangzhou 310027, China)

Abstract: In order to solve the problems of that Liion battery charging speed needed to be improved, while the best charging strategy issues of different types of lithium batteries vary. The advantages and disadvantages of different charging circuits and proposed was investigated. A fast charging circuit based on DSP28035 for lithium battery charging was presented to study on the fast charge method for lithiumion batteries. Battery voltage and current were collected by DSP28035 with digital closedloop control. A wide range of input 6 V-30 V was possessed with Buck converter for battery charging and Boost converter for pulse discharge depolarization. Battery charge and discharge current could be controlled accurately. CC, CV, CCCV and the staircase constant current charging, pulse charging and other forms of charging could be achieved through changing the DSP program. The lithium battery charging was tested by MATLAB/Simulink and charging prototype. The experimental results show that the circuit has the correct principle, simple structure and convenient control, which can be used for various charging strategy test. It can realize overcurrent, overvoltage and overtemperature protection. The circuit has good stability and high reliability.

Key words: lithium battery; fast charging; pulse charging circuit; DSP control