| The dual pressures of energy shortage and environmental pollution are restricting the development of China.Electric vehicles(EVs)have become the development trend of the vehicles industry because of the demand for energy conservation and environmental protection.Power Battery is the energy source of electric vehicles.affecting the power,safety and economy of the whole vehicle.How to manufacture and manage power batteries has become the key to the development of electric vehicles.Power battery inconsistencies exist in terms of voltage,capacity and resistance,and these inconsistencies continue to increase as batteries continue to be used.In order to meet the voltage and capacity requirements of electric vehicles.the power batteries are used in the form of battery pack.The inconsistency problem may cause overcharge or overdischarge of battery pack,which may cause safety problems.Therefore,it is necessary to perform multi-parameter data acquisition for the power battery pack and its cells.This paper designs a multi-parameter and high anti-interference data acquisition system for power battery pack.The main contents include:(1)After clarifying the multi-parameter data acquisition requirements,system functions and performance indicators of the power battery pack,the overall scheme of the system is designed.The system adopts a modular design concept,including a main control module and different data acquisition modules.In view of acquisition unsynchronization.data transmission congestion and data loss in the data transmission process,the system uses a multi-core parallel control architecture based on Field Programmable Gate Arrays(FPGA).For the interference in power battery pack data acquisition process,the system adopts a high anti-interference data acquisition scheme.including the design of the data acquisition system based on electrical isolation and the interference elimination measures based on signal integrity analysis.(2)The hardware and software of the system are designed for the difficulty and speciality of data acquisition of power battery pack.The data acquisition circuit mainly includes the voltage acquisition circuit of the cell in series-connected batteries,the current acquisition circuit of the cell in parallel-connected batteries,the total voltage and total current acquisition circuit of the battery pack,and the temperature acquisition circuit.(3)In order to verify the effectiveness of the system,an experimental platform was set up.The experiments mainly incloude the experiment of static and dynamic characteristic,the voltage acquisition experiment of the cell in series-connected batteries,the current acquisition experiment of the cell in parallel-connected batteries,the total voltage and total current acquisition experiment of battery pack,the battery temperature acquisition experiment.The experimental results show that this system can achieve the expected functions and performance indicators.(4)Research on modeling the power battery pack with the data acquired by this system.Based on the cell’s Thevenin model,the series-connected battery pack was modeled with separate model and overall model respectively.They are validated under the UDDS and DST conditions.Due to the inconsistency of batteries,there are larger errors in the overall model,which highlights the necessity to acquire data for each cell synchronously in the process of researching the battery pack performance.The power battery data acquisition system designed in this paper can carry out multiparameter acquisition and has strong anti-interference,high acquisition accuracy and good synchronism.It has important scientific research value and can effectively promote the development of power battery and electric vehicle. |
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