增程式电动车动力电池组低温行车预热策略

为了提高动力电池组低温环境下的放电效率，针对增程式电动车低温行车条件，考虑电池组预热过程中单体温度的不一致及单体排布等因素的影响，进行增程式电动车动力电池组低温行车预热策略研究。采用Chrom_17011充放电测试机及高低温恒温箱对26650磷酸铁锂电池单体进行低温试验与AMESim模型仿真对比的方法验证预热模型的精度，分析发动机怠速为电池组进行预热时，水泵转速、串行通风鼓风量、串行通道单体数量及单体与单体之间的间隙对电池包内入、出口单体温差的影响。通过整车仿真，分析行车预热策略与传统CDCS策略在不同环境温度下对等价燃油消耗量的影响。研究结果表明：在单体排布间距固定和水泵转速为800 r·min^-1的条件下，电池包串行通风风量越大，串行通道入、出口单体温差越小，单体预热时间相对较长，且在串行通风风量不小于3 g·s^-1的条件下，能满足电池包串行通道最大温差小于5℃的要求；环境温度在-20℃时，行车预热策略比CDCS策略等价燃油消耗率降低16.25%，纯电动续驶里程增加9.95 km；其影响等价燃油消耗率的因素有制动能量回收量和内阻消耗量，内阻消耗量是影响等价燃油消耗率升高的主要因素。

Preheating Strategy of Extended-range Electric Vehicle Power Battery Packs for Low-temperature Driving

The goal of this study is to improve the efficiency of discharge power battery packs, in view of the low-temperature driving conditions of extended-range electric vehicles, considering the effect of factors such as the inconsistency of the monomer during the preheating process and the arrangement of the monomer. The accuracy of the preheating model was verified by comparing the low temperature test of the 26650 lithium iron phosphate battery using a Chrom_17011 charging and discharging test machine and high and low temperature incubator with the simulation results of the AMESim model. By analysis of the engine idling to preheat the battery pack, the pump speed, the effects of the serial ventilation blast volume, the number of serial channels, and the gap between the monomer and the monomer, and the temperature difference between the inlet and outlet of the battery pack were obtained. Through vehicle simulations, the effects of the proposed preheating strategy of low temperature driving and traditional CDCS strategy on the equivalent fuel consumption at different ambient temperatures were analyzed. The results of the simulations demonstrate, under the conditions that the arrangement distance of the monomer is fixed and the speed of the pump is 800 r·min^-1, the greater the serial air flow rate of the battery pack, the smaller the temperature difference between the inlet and outlet unit of the serial channel, the longer the monomer preheating time, serial ventilation air volume is greater than or equal to 3 g·s^-1 conditions, to meet the requirement of the maximum temperature of the battery pack serial channel being less than 5℃. When the ambient temperature is -20℃, the preheating strategy of driving according to the CDCS strategy is decreased by 16.25% on the equivalent fuel consumption rate and increased by 9.95 km on pure electric driving range; the factors that affect the equivalent fuel consumption rate are the amount of brake energy recovery and internal resistance consumption, and the internal resistance consumption is the main factor affecting the increase of the equivalent fuel consumption rate.