High-precision Voltage And Current Detection System Research And Design Of Lithium Batteries Module Of Electric Vehicle

Electric vehicles are a new type of power to the power supply environment-friendlyautomotive products and it has been highly valued in many countries. Li-ion battery graduallyhas become one of the best choices of electric vehicles drive battery for its long life,cost-effective, fast charging and green advantages. To Li-ion battery packs voltage, electricityaccurate measurement is the battery management system to be solved technical problems.Currently Li battery packs have many methods to check single battery voltage, but in thesemethods are existing low precision, high complexity and large size shortcomings. The paperset from the national “863” research projects requirements researching and design a sort ofhigh precision voltage and electricity detection systems based on CAN. Circuit takes effectivemeasures and error compensation technology to achieve a high precision technicalrequirement.The paper researching system consists of seven battery modules and control unit. UsingCAN-based distributed architecture that all of the battery pack module and control unitthough CAN put up data transmission and exchange. Battery system has good scalability andversatility for it can increase or decrease the number flexible.Firstly, the text introduces the research background, significance and motive powercommonly used in electric vehicles of the topic, to focus on analysis battery managementsystem’s development status and check precision of voltage and electricity to estimate the restelectricity measure influence of battery pocks. Setting from Li-ion battery technologyfeatures using its voltage, temperature, charge and discharge and cycle life characteristics asbasis research and design performance better voltage and electricity check system and makebattery life and optimum achieve best. Secondly, to gather battery pocks single batteryvoltage making a more in-depth study. To particular describe battery pocks single batteryvoltage collection method based on “flying capacitor” technology. The method has littleimpact on the battery; circuit is simple, reliable and high precision characteristics (error lessthan0.1%at room temperature). For the detection of electricity battery pocks, designed hardware circuit of collection electricity make use of Hall sensor and processing static erroranalysis of check system. Finally, the text has been designed the system software and tointroduce the check results correction method of the application digital filtering techniques.Software design process using multi-working procedure equally dealt process structure; theprocess structure designed to be simple, real time strong and can be well response detectionsystem on system stability and real-time requirements.The paper gives out the detection system simulation results and experimental data. Theexperimental results show that the voltage and electricity measurement accuracy to meetsystem design requirements.