基于电-热耦合模型的动力电池双向脉冲低温预热特性OA

To address the issues of low temperature rise efficiency and high energy consumption in the low-temperature pulse preheating of current power batteries,a square ternary lithium-ion battery was taken as the research object,and an electric-thermal coupling model was established.A bidirectional pulse with equal amplitude ratio was designed for the low-temperature preheating of the battery.The simulated temperature,voltage and preheating energy consumption of the battery cell under a 2 C equal amplitude ratio bidirectional pulse with an equal amplitude ratio were compared with the experimental values,and the relative error of the established coupling model was verified to be less than 4.39%.Meanwhile,under the ambient temperature Tamb=273.15 K and battery SOC=0.1,the effects of different pulse periods SR,current amplitudes I,amplitude ratios IP/IN and pulse intervals SI on the battery average temperature T and total preheating energy consumption Etotal were analyzed when the preheating time t=1 800 s.The results show that when I=3 C,both T and Etotal reach the maximum values,which are 290.93 K and 254.19 kJ,respectively,for the bidirectional pulse with equal amplitude ratio.While the Etoal of the bidirectional pulse with variable amplitude decreased by 27.8%and T decreased by 0.91%compared with the constant amplitude ratio at I=3 C.Within t=480 s,when IP/IN is larger,T shows a trend of first increasing and then decreasing,and Etotal shows a trend of first decreasing and then increasing,but the overall temperature change does not exceed 0.07 K.The bidirectional pulse with equal power interval SI of 6 s has a 12.85 K higher T and a 5.1%lower Etotal than the bidirectional pulse with SI of 0 s.