Design And Development Of The Life Test System For Lithium-ion Battery

With the progress of society and the development of science and technology,the automobile industry has entered a new era,which has begun to develop in the direction of “electricity”.As the core energy storage device for electric vehicles,the development of battery technology has received widespread attention from the society.The battery life is a key parameter of the battery performance.However,it is difficult to be measured directly.And it requires a long-term and large number of tests to conduct research.In response to this demand,this paper designs and develops a set of hardware and software systems for lithium-ion battery cycle life testing based on current domestic regulations for lithium-ion battery life testing.The specific work is as follows:(1)Investigate domestic and foreign literature and regulations,determine the functional requirements of the charge and discharge test system,and design plans for hardware and software.Summarize the main factors affecting the life decay of lithiumion batteries and mainstream battery life prediction methods at home and abroad.According to the battery life test standards,this paper defines the battery life testing process,determine the charging conditions for the battery cycle life test requirements.What's more,we have determined the battery cycle life testing hardware and software solutions based on the dual-DC-DC main circuit topology by combining the operating voltages,current control requirements and requirements for operating speeds.(2)Completed the design and debugging of system software and hardware.Completed hardware design of the main loop,signal acquisition conditioning circuit and the main control circuit.The main circuit part of the charging adopts the Buck circuit,and the main circuit of the discharging adopts the Boost circuit.The design of the dual circuit can realize the fast switching of the charge and discharge of the battery.The main control circuit adopts Infineon XC2000 series MCU to achieve voltage and current control algorithm and life test system communication with the host computer.Software development includes voltage and current control algorithms and PC monitoring software.The voltage and current closed-loop control can realize the constant voltage/constant current charge/discharge control of the battery.The host computer software adopts the serial port to communicate with the single-chip microcomputer to realize the automatic control of the battery charging condition and the real-time display and storage of the battery voltage and current test data.(3)Completed the experimental test of the constant voltage and constant current charge and discharge functions of the lithium ion battery cell.Through setting various tests condition of the upper computer,it has verified the system's function of the battery's cyclic replay test and the reliability of the continuous data acquisition of the host computer,verified the effectiveness of this system for the lithium-ion battery cycle life test as well.