Research On A Wide-measuring-range And High-accuracy Battery Data Acquisition System

Under the growing trend of electric vehicles, power battery applications have also increased. Power battery pack is composed of series-parallel connected cells. The inconsistency of the cells can decrease the battery pack performance, including cycle life, output power, etc. A serious impact on the development and application of electric vehicles is induced by the inconsistency. Therefore, the packing inspection and periodic performance testing is a key link to assemble a high-performance battery pack, which performs more reasonable and economic usage of the battery.This thesis is based on a battery pack testing platform. In the consistency test, many data acquisition systems do not have sufficient data precision and synchronism. A synchronous high-precision battery data acquisition system is developed. This system contains independent cell voltage acquisition units, and it has a parallel-sampling mode. Each unit consists of independent single acquisition module with distributed stucture. In the parallel-sampling mode, all units’data upload to the data bus simultaneously. By getting the Sync signal from the data buses, system synchronism is achieved.In this thesis, by comparing cell data acquisition technology among a variety of sensors and the ADCs, and analyzing the factors affected the accuracy among signal processing circuits, both the hardware and software of the system are propose, also the deviations of each part of the acquisition circuit are analyzed and PCBs are designed, ultimately a wide range of precise battery voltage, current, temperature data collection is achieved. Finally, according to the experimental data, the feasibility and high-precision of the synchronous acquisition in this system are proved, and also a reliable and precise base for battery consistency testing is provided.