动力电池组汇流排热电耦合数值计算与实验研究

以某电动汽车动力电池模组汇流排为研究对象,提取汇流排的三维数模、工况边界条件以及与电池单体的连接关系,采用热电耦合数值计算方法研究电流大小、对流换热系数以及焊接工艺对汇流排温升的影响规律.为保证数值计算的准确性,采用动力电池组综合测试系统对指定的不同工况进行温升试验测试,试验测试工况条件与数值计算中的边界设置保持一致.研究表明,网格离散、边界条件、电流大小、对流换热系数以及极耳焊接工艺都会对汇流排的温升产生不同程度的影响.针对个别工况下数值计算与试验测试结果误差较大的情况，详细分析误差产生的原因,深入研究因素之间的关联性以及对误差的影响规律,进而对数值计算模型进行修正.最后,设定新工况再次对汇流排进行数值计算和试验测试,运用因素的关联性和对误差的影响规律,数值计算与试验测试结果的误差不超过3.7%.

Numerical Calculation and Experimental Research on Thermoelectric Coupling of Power Battery Module Bus-bars

Taking the battery module bus-bars of an electric vehicle as the research object, the 3D digital of bus-bar, working boundary conditions, connection relationships between bus-bar and battery cells were extracted. The influence rules of current size, convective heat transfer coefficient and pole welding process on the temperature of bus-bar were studied by numerical method of thermoelectric coupling. In order to ensure the accuracy of the numerical calculation, the dynamic battery pack test system was used to investigate the temperature variance of the specified working condition. The test condition was consistent with the boundary setting in the numerical calculation. The results show that the grid partition, boundary condition, current size, convective heat transfer coefficient and pole welding process have different effects on the temperature rise of the bus-bar. As the error between the numerical calculation and test result occurs in some working conditions, the reason was analyzed in detail. The correlation between the factors and the influence law of the error were also further studied, and then the numerical calculation model was modified. Finally, under the new working conditions, the numerical calculation and experimental measurements of bus-bar were carried out. Through using factor association and the influence rule on the error, the error between numerical calculation and experimental measurement was within 3.7%.