Research And Design Of Battery Equalization System

In order to putting lithium-ion battery into used widely, the precondition is that it should be used in group, the inconsistency of battery pack impedes the spread and the application of it. In terms of the performance and the battery service life, there is a huge difference between the battery pack and the single one because of the inconsistency of the single battery. Excepting the diversity made by the manufacturing process, the major factor is that it was charged unbalanced during the using time. In this paper, the purpose is to design an equalization charging system for lithium-ion battery pack.At first, the inconsistency problem of the battery pack and battery equalization charging control strategy were studied; Secondly, according to the current equalization technology analysis in engineering application, the battery equalization technology are discussed in-depth comparison, including various equilibrium circuit topology structure and equilibrium charging; Thirdly, we build the lithium-ion battery equilibrium system model based on the Matlab/Simulink software and simulate the equilibrium charging state. The simulation results showed the effectiveness of the equilibrium charging system. The software of equilibrium system is designed and the equilibrium strategy is established, including the main program, communication program and the design of the data acquisition subroutine.According to the simulation results, In this paper, we made a research on the equalization charging system based on DC-DC, selected the MC9S08DZ60 as the main control chip,then connected it with the battery monitoring chip LTC6803. In this design, including external circuit of the corresponding chip, data acquisition circuit,power supply circuit, protection circuit, equalization circuit and switching circuit,designed the hardware on the equalization charging system which can equalize 12 series battery pack. Engineering application examples showed that the hardware and software design of this system satisfied the needs of the project. The equilibrium system improves the efficiency on the battery pack.