The Design And Implementation Of Lithium-Ion Battery Management System

Since the end of the 20th century, Lithium ion battery has aroused the concern of people and been widely applied to a variety of electrical equipments, such as standby power, mobile phones, laptops, electric vehicles and aviation devices.Because of the low voltage of the single cell lithium ion battery, the battery pack is composed of a plurality of cells in series in the practical application.However,the battery pack’s overheating,over-voltage and under-voltage will shorten the service life of the battery pack,even cause fire,explosion and other security problems,which requires the confirguration of the battery pack management system to manage the battery group.As a result,Lithium ion battery pack management system becomes the key enquipment to solve the problems of service life and safety,and plays a vital role in ensuring safe usage and prolonging service life for the batter group.First of all, the work characteristics of the lithium ion battery pack and its management technologies are analyzed in this paper. And the actual function requirements of the lithium ion battery pack management system including balance management, charging management, temperature management, capacity estimation and serial port communication are summarized in this paper.In terms of its function management, the energy dissipative equalization strategy is applied to solving the charging and discharging inconsistency of the battery pack,the pulse current charging mode is used to the battery’s charging, open circuit voltage method is adopted to estimate the residual capacity with ampere-hour integral method, RS-485 serial port is used to exchange data with other systems.Secondly, hardware design and software design for the system are expounded in this paper.According to the overall design scheme of the system, the hardware circuit of the system are designed in this paper including data acquisition unit, banlance control unit, temperature control unit, serial communication unit and fault detection unit.Subsequently, software function demands of the system are summarized in this paper.Then, the software design process and softaware coding for the system are expounded in this paper with modular design method,including data acquisition, charging control, balance control, temperature control, capacity calculation and the serial communication.Finally, the debugging process of the system is expounded in this paper with the PC monitor interface,the debugging results show that the system can run safely and reliably,and meet the management requiremets of the battery pack.