车用电池包结构动力学建模及分析方法研究

Study on the Method of Structural Dynamic Modeling and Analyzing of the EV’s Battery Pack

汽车动力电池包多由单体电池、模组、壳体、电器联接部件及管理系统装配成整体,在变温、振动环境下完成充放电功能。其性能的可靠和安全直接决定了电动汽车的正常运行。研究复杂电池包结构的动力学建模和分析,探索其内部精细结构以及整体电池包的动力学响应,是车用电池包开发和结构、性能优化的迫切需要。提出了基于单体等效力学参数和实际接触连接条件的复杂电池包系统建模和动力学分析方法,结合电池包开发实例,建立各部分子模型并进行试验验证,通过优化算法确定最佳接触参数;对比集中质量模型、简化连接模型、接触模型的模态仿真结果,验证所建模型的有效性和精度,说明建模方法的可行性;获得了实例电池包内部关键电接触点在随机振动下的响应,发现同一振动工况下不同位置触点的加速度响应差异很大,呈现很强的不均匀性。给出了螺栓连接的电池包装配体动力学精细化建模方法和分析思路,对同类型电池包结构设计、安全性分析有实际意义。

The EV’s battery packs whose reliability and security performance directly determine the EV’s normal operation mostly assembled into integration by battery cells, modules, shell, electrical connection components and management system, completing the charge and discharge function under the vibration and varying temperature environment. It’s an urgent need to study on dynamic modeling and analyze of complicated battery packs and explore the dynamic response of internal fine structure and the whole integration during the developing and optimizing procedure of battery packs. The method of complicated battery packs systemic dynamic modeling and analyzing based on the cell’s equivalent mechanical parameters and actual contact conditions is proposed. Combined with the development of a battery pack instance, each sub-model is established and under experimental verification. The optimum contact parameters are determined by optimization algorithm. The simulation results of mass-concentrated model, connection-simplified model and contact-considered model are compared to experimental result to verify the validity and accuracy of the model and the feasibility of the method. The random vibration responses of instance’s internal key electrical contact points are achieved and show that different positions have big difference under a same vibration excitation and the responses are highly non-uniform distribution. The method of dynamic modeling and analyzing of bolt-connected battery pack is proposed and has practical significance to the design and safety analysis of the same type battery packs.