Research And Design Of The Battery Management System Focus On Small Capacity Battery Packs

Electricity,an environment-friendly energy,can be converted from hydro energy and solar energy.It is different from traditional fossil energy,not only can reduce exhaust emission,but also avoid energy crisis in many countries caused by fossil energy shortage.As a kind of independent electricity storage,battery plays a significant role these days.For example,power type lithium-ion battery groups are always used by many kinds of automatics to provide power,including electric vehicles,unmanned aerial vehicles and mobile robots.In order to improve the effectiveness and reliability of battery groups,it is vital to apply BMS to manage and control the groups.Meanwhile,BMS could secure the normal operations of groups.Given rapid development of electric vehicle industry,researches on BMS,which traditionally focus on large storage batteries,are not suitable to rising industries,e.g.low-speed electric automobile,moped and robot.Based on characteristics of Li(NiCoMn)O2-lithium battery,this paper concentrates on designing a battery management system for small capacity battery group.According to the research and testing on Li(NiCoMn)O2-lithium battery,the battery model was built with characteristics of hysteresis voltage and rebound,having the equivalent voltage source and equivalent resistance.By combining model with UKF,the model is able to estimate residual quantity.Functions in the BMS include estimation state of charge,uniform or flat management,current voltage detecting,data communication,thermal management,security and display.Overall,the system is accomplished by distributive method,which means it is divided into control and detection unit.Moreover,applying FreeRTOS into software developing not only increases efficiency on the usage of resources but also improves real-time update of system.Furthermore,computer-human interaction is fulfilled by the parameters shown on the MFC.The small-capacity battery management was verified to meet the requirements and feasibility.Finally,the whole system is tested by connecting battery to battery management system and comparing important parameters like electric pressure,current,temperature within experimental environment.All data is collected and tested against data sample precision.As conclusion,the system has capacity to meet requirements.