多拓扑结构锂电池组外短路特性分析及模型评价

Model Evaluation and Analysis for Multi-topology Lithium Battery Pack External Short Circuit Characteristics

新能源汽车的快速发展受到动力电池系统安全的掣肘,锂电池组外部短路故障是导致电池热失控进而引发汽车起火爆炸的主要因素之一,而不同拓扑结构及初始荷电状态(State of charge,SOC)影响锂电池组外部短路特性。搭建锂电池组外部短路故障试验平台,进行多拓扑结构锂电池组在静置工况下的外部短路试验,模拟汽车停置时电池发生外部短路故障过程,揭示不同拓扑结构及不同初始SOC对锂电池组外部短路特性的影响,为锂离子电池单体分选成组、外部短路故障诊断等方面提供数据支撑。此外,锂离子电池外部短路模型重构是进行故障诊断的基础,对不同等效电路模型对锂离子电池外部短路电压预测精度等进行综合评价,为锂离子电池外部短路电特性重构模型选择提供指导。

The development of electric vehicles is hampered by the safety of power batteries.The external short circuit fault of lithium-ion battery pack is one of the main factors that lead to the thermal runaway of batteries and the fire and explosion of vehicles.Different topologies and initial SOC conditions of the lithium-ion battery pack affect the characteristics of external short circuit fault.This paper conducted the external short circuit test of Muti-topology lithium-ion battery pack,which is in the static condition,with designing the lithium-ion battery pack external short circuit fault test platform.The test reveals different topology and different initial SOC influence on lithium-ion battery pack external short circuit characteristics,with the simulation of vehicles in the rear external short circuit fault process.And it provides data support for the lithium-ion battery cell sorting into groups and external short-circuit faults detection.In addition,the reconstruction of external short circuit model of lithium-ion battery is the basis for fault detection.This paper comprehensively evaluates the prediction accuracy of external short circuit model by different equivalent circuit models,which provides guidance for the selection of external short circuit model of lithium-ion battery.