Research On The System Of Lithium Battery Management Of Hybrid Power Motorcycle

Environmental pollution and energy crisis have become an important factor in restricting the development of the world. Hybrid vehicles, which meet the needs of the development, reduce fuel consumption and emissions, compared with traditional fuel vehicles. Hybrid vehicles is driven by electrical and fuel power.most potential electrical power is lithium-ion battery, which is high energy density, high charge efficiency, long battery life, and the single battery charge and discharge more than 2000 times, lithium battery pack’s life is up to 500 charge-discharge and the high price of hybrid vehicles to replace a battery needs to be a higher fee. Articles shows that:the differences between batteries and poorer charge-discharge state are mainly reduce the battery pack life. So, improving lithium-ion battery life is necessary. Battery management system is used to improve the life of the lithium-ion battery, so the research work is forcus on it.In the study, the lithium batteries use 18650 Model, made by ternary material, which is composed of 13 battery cells connected in series. The management system is composed by the host controller and minor controller power switch, and communication with the vehicle controller by CAN bus. The core of the whole control system is PIC18F46K80 chip. By the charging circuit, protection circuits, data acquisition circuit, a balanced circuit, display circuit, memory circuit, communication circuit, the alarm circuit. The article’s main research work and results achieved are as follows:(1) For the lithium-ion battery long charging time, with high battery temperature, the paper presents three-stage charging intelligent, pre-charge voltage of alternating current charging, constant current charging and constant voltage,using fuzzy control and intelligent control algorithm, based on the adjustment of the battery SOC and temperature smart charging voltage and current. The experiments show that the charging time keeps in 185 minutes, maximum temperature 38℃, the charging process, reduce the damage caused by the battery temperature increases.(2) By the temperature and detection accuracy is not accurate detection of the remaining battery phenomenon, the paper proposed, combined with intelligent correction based on the open circuit voltage and Ah counting method to accurately detect. The experiments show that the battery during charging and discharging several times by the controller detect and compare the last remaining battery power correction can predict the remaining capacity accuracy, laid the foundation for the formulation of the vehicle control strategy reduces due to the remaining The battery indicator inaccurate control strategy misuse damage the battery.(3) For the lack of differences between single cells, the paper proposes a lossless balanced approach-balanced transformer, not only to achieve the balance between the single battery charge and discharge, and also to protect the poor performance of the battery played a performance than good battery performance. The experiments show that a balanced, high efficiency, working pressure equalization circuit can be stored as part of the energy sharing of individual cells, improve the ability to protect the battery.