The Design Of Battery Management System For New Energy Vehicles

People's demands for cars are increasing with the progress of society, and thedevelopment of automobile industry has been promoted greatly while fossil fuels aredepleted.Contaminants in the air increased due to the growth of the number of carswhich affects people's health greatly,Therefore, the development of new energyvehicle technology has become a hot point of research.Battery Management System(BMS) is an important part of new energy vehicles,It ensures new energy vehiclesrunning safely and efficiently,but also can obtain the maximum efficiency andservice life of the battery.Therefore, the design of the battery management system isessential for the new energy vehicles.In this thesis, master-slave structure is designed according to the specificrequirements of the battery management system, the microcontroller of the localmodule is MC9S08DZ60from Freescale,LTC6804is used to monitor the batteryvoltage.Battery temperature is detected by the sensor,the microcontroller of themaster module is MC9S08DZ60from Infineon,Master module used to implementdata processing and preservation.The paper also describes a detailed scheme aboutthe collection for total battery voltage, current.This paper summarized the reasons for the inconsistency on the battery?andcompared several topologies for battery equalization. Papers selected bidirectionalflyback converter as the battery equalization scheme which can charge anddischarge the battery optionally.One of the difficulties of the BMS is the estimates of the SOC.Firstly,the paperselected Kalman filter algorithmhis as the primary method, Taking into account theamount of computation and accuracy, The paper selected second-order RC modelby comparing the different battery models,and improved the cell model byconsidering the influence of temperature.Model parameters can be obtained a byusing an improved battery least squares method. Finally,SOC can be calculatedbycombining EKF and RLS.