首先通过最小二乘法对方形锂离子电池组中单体电池的比热容、流道材料的导热系数和自然冷却条件下的综合换热系数进行了估计；然后根据热边界层理论确定了强制冷却条件下电池冷却流道表面局部综合换热系数的计算式；最后根据电池组的结构特点和冷却方式,建立了电池组的一维瞬态传热模型.该模型能根据电池组当前的环境温度、运行负荷、冷却强度和初始荷电状态实时预测电池组中各单体电池的运行温度.在Arbin试验台架上测量了144V/8A·h方形锂离子电池组在不同运行工况下单体电池的温度分布,并与模型仿真结果进行了对比,结果表明模型仿真的最大误差不超过1℃,满足混合动力系统性能仿真和电池组管理策略优化的精度要求.%Firstly, the specific heat capacity of battery cell and its overall heat transfer coefficient under natural cooling condition as well as the thermal conductivity of cooling channel material in a square lithium-ion battery pack are estimated by least square method. Then calculation formulae of local combined heat transfer coefficient of cooling channel surface under forced cooling condition are worked out based on thermal boundary layer theory. Finally a one-dimensional transient heat transfer model is set up according to the structural feature and cooling mode of battery pack. With the model, the operating temperature of each cell in battery pack can be predicted realtime according to ambient temperature and the operating load, cooling intensity and initial SOC of battery pack. The temperature distribution of battery cell in a 144V/8Ah square lithium-ion battery pack under different operation conditions are measured on a Arbin test bench and compared with that by model simulation and the results show that the maximum error of model simulation in temperature is only 1 °C , meeting the accuracy requirements for the performance simulation and battery pack management strategy optimization of hybrid power system.
展开▼
