无模组动力电池包振动特性研究

Study on Vibration Characteristics of Mode-free Power Battery Pack

为探讨某车用无模组动力电池包的振动特性,建立了不同电芯尺寸和电芯布置的两种电池包有限元模型;基于所构建的电池包有限元模型,在3种极限工况下,对两种电池包进行静力学分析与模态分析;基于分析结果对电池包进行改进设计。研究表明,动力电池包中的电芯尺寸及电芯布置方式对电池包的振动特性具有显著影响;电池包1.0的上盖刚度不足,其最大应力和上盖最大变形量都较大,1阶约束模态固有频率低于平整路面的最大激振频率,易导致动力电池包共振;动力电池包2.0具有较好的静力学特性,且其1阶固有频率高于平整路面的最大激振频率,可避免路面激励导致的电池包共振;上盖改进后动力电池包1.0的静力学特性和振动特性均能满足要求;增加电池包的约束范围可以提高其1阶固有频率。

In order to investigate the vibration characteristics of a mode-free battery pack for an electric vehicle,two simplified finite element models of battery packs with different cell sizes and cell layouts were established.Based on the finite element model of the battery pack,the static analysis and modal analysis of the two battery packs were carried out under three limit conditions.Based on the analysis results the improved design was performed on the battery pack.The results show that the cell size and cell layout in the power battery pack have significant influence on the vibration characteristics of the power battery pack.The upper cover stiffness of battery pack 1.0 is insufficient,the maximum stress and maximum deformation of the upper cover are large,and the natural frequency of the first order constrained mode is lower than the common road excitation frequency,which is likely to cause resonance of battery pack.The power battery pack 2.0 has good static characteristics,and the first-order natural frequency is higher than the common road excitation frequency,which can avoid resonance with road excitation.After the improvement of the upper cover,the static and vibration characteristics of the power battery pack 1.0 can meet the requirements.Increasing the confined range of the battery pack can raise the first-order natural frequency.