Research On Power Battery Management System

As an energy source,power battery is a key to the performance of an electricvehicles.How to make power batteries work with the electric vehicles perfectly,and make thebattery to play the greatest efficiency and extend battery life.those are the questions thatbattery management system should solve.This study targeted a battery management system(BMS).First of all,we need tounderstand the performance of battery, so the battery model is built by Advisor software usedin the matlab/simulink environment.This model is the establishment of the RC model of thebattery, the model's parameters in real-time changes as the battery state changes,therefore,thismodel can simulates power batteries well. In addition, the temperature of the battery packhave a greate impact on the performance of batteries.This model also includes a thermalmodel,which can turned on the fans when the temperature is above the giving value. Thesimulation results show that the cooling system works well.After the specific function distribution of BMS, In this thesis, Motorola chipsMC68HC908GZ16is choosen as the main chip for the sampling system, and the specifichardware circuit design of the voltage sampling and current sampling and temperaturesampling is completed. In this paper, instead of the traditional analog voltage switchingdevices,a CPLD device EP2C5T144C8N is used for select the btteries sampling.In thisway,not only improve the conversion rate, and the rich interfaces of CPLD device could beenused for the future expansion of BMS.In addition, this paper also design a functionality CANbus,which is defined by the various functions of the message.In software design,theis paper design module initialization, sending and receiving data ofMSCAN08module in MC68HC908GZ16.In the lab environment, the sampling system module test was proceeded. The mainmeasurement is testing the voltage of each single cell in the battery pack. The voltmeter testdata results show that the sampling module is working well and the sampling accuracy canmeet the design requirements.