低温下电池系统台架试验液冷控制方法的优化研究

随着电动汽车快速发展,对动力电池性能的要求日益严苛,电池热管理技术的升级优化变得十分迫切。由于国内缺乏电池系统试验水冷控制策略规范,台架试验与整车试验中的电池系统性能表现差异较大,导致试验结果严重脱节,系统级试验失去了原有的测试验证意义。本文对液冷台架试验方法的实际应用开展研究,通过功率、冷却液比热容、进出水口温差、流量等因素的关联计算,优化了电池系统台架液冷控制方法,使台架试验能够更好地模拟实际整车水冷情况。通过对电池系统进行 -20℃低温快充、-10℃低温快充和 -20℃低温慢充三项试验,验证了该电池系统台架液冷控制方法在低温下的改善效果。相较于传统台架液冷试验方法,采用该液冷控制方法能够使电池系统的温度及电性能更符合实际整车变化,保证了电池系统在系统级试验阶段与整车级试验结果保持一致,实现了电池系统在台架液冷试验的真实性能考核。

Optimization of Liquid Cooling Control Method for Battery System Bench Test at Low Temperature

The requirements for the performance of power batteries are more and more stringent as the rapid development of electric vehicles, so the upgrading and optimization of battery thermal management technology is urgent. Due to the lack of battery system test water-cooling control strategy specifications in China, the performance of the battery system in the bench test and the vehicle test is quite different, resulting in a serious disconnection of the test results, and the system-level test loses the original test verification significance. In this paper, the practical application of liquid cooling bench test method was studied, and the liquid cooling control method of the battery system was optimized by the correlation calculation of power, coolant specific heat capacity, inlet and outlet temperature difference, flow rate and other factors, so as to simulate the actual water cooling better. The improvement effect of the battery system bench liquid cooling control method at low temperature was verified by three tests of -20^oC fast charging, -10^oC fast charging and -20^oC slow charging of the battery system. Compared with the traditional bench liquid cooling test method, the temperature and electrical performance of the battery system were more consistent with the actual vehicle changes by using the liquid cooling control method in this work, which ensured the consistency of the battery system in the system-level test phase and the vehicle-level test results.