Research On Battery Management Technology Based On Wireless Monitoring

With the continuous progress of society,cars have become a necessity in people’s life.Many cars not only consume a lot of petroleum energy every day,but also produce a huge amount of cars exhaust which causes environmental pollution.More and more people will choose electric vehicles when they buy vehicles in order to save oil energy and protect the environment with the rapid growth of electric vehicle sales in recent years,the traditional fuel vehicles will be replaced by electric vehicles which will become an inevitable trend.Battery management system(BMS)is one of the three core components of electric vehicles,which can intuitively inform users of the remaining mileage of the battery,improve the service life of the battery and prevent battery safety problems.The 48V battery package was taken as the research object in this paper.The battery management technology based on wireless monitoring was studied and it builds the test platform by building hardware circuits,controller programs,master computer,and verifies the system design.The specific work contents are as follows:(1)Firstly,the working principle of lithium-ion battery was analyzed.The state of charge(SOC)of lithium-ion battery was estimated by comparing with existing methods.PSO-BP neural network algorithm was proposed to estimate battery SOC,and then the public data sets from the NASA were used to predict and compare on the MATLAB platform.The results show that the estimation error of this method is less than 2%,and it has a relatively high accuracy.(2)The master-slave topology was adopted to build the hardware platform,the hardware selection and design of each functional module which in battery management unit(BMU)and cells management controller(CMC)are completed.The master-slave architecture of one master and three slaves was adopted in the BMS,that is,one battery management unit manages three cells management controllers.The total voltage measurement,insulation detection,data communication and fault alarm were included in the tasks of the BMU.The voltage acquisition,current acquisition,temperature acquisition,balance control and data communication were included in the tasks of the CMC.(3)The NRF24L01 radio frequency chip was used for wireless communication between BMU and CMC which for replacing the traditional wiring harness to transmit data.The limitation of battery layout caused by the wiring harness,the difficulty of later maintenance,and the safety problems were avoided by this method.At last,the reliability and stability of wireless communication were tested via the experiments.(4)The master computer was programmed based on the Labview platform to achieve human-computer interaction.It was communicated with the BMU through the USART port.The battery voltage,temperature,current,SOC,fault alarm type and historical data storage function was displayed in real time.(5)Finally,the acquisition unit,the main control unit and the upper computer are jointly debugged.The test results show that the system meets the design requirements and can complete the functions of battery data collection,battery balancing,SOC estimation,fault alarm,and human-computer interaction.