Abstract: The use of multiple battery packs in series and parallel in the power battery system of new energy commercial vehicles can cause the risk of thermal runaway in a single battery pack due to insulation failure, incorrect high-voltage cable connection, etc. This paper takes 8 standard battery packs connected in 4 series and 2 parallel configurations to form a power battery system as an example to study the failure and thermal runaway reasons of charging a single battery pack by multiple battery packs in series. It is suggested to use high-energy type cells and to connect battery packs in series or to configure intelligent fuses in the battery packs to avoid such risks. Analysis shows that battery pack series connection can avoid the risk of charging a single battery pack by multiple battery packs in series, and intelligent fuses can cut off fault current within 0.5 seconds, effectively preventing thermal runaway.

Key words: commercial vehicles; power batteries; battery pack; thermal runaway

摘要： 新能源商用车采用多个电池包串联后再并联的动力电池系统在发生绝缘失效故障、高 压线束连接错误等故障时，会造成多个电池包串联后对单个电池包充电引发动力电池热失控 的风险。文章以 8 个标准电池包通过 4 串联 2 并联组成的动力电池系统为例，展开多电池包 串联对单电池包充电故障及热失控原因分析。建议选用高能量型电芯并采用电池包串联或将 电池包内配置智能熔断器的方案规避此类风险。经分析电池包串联可规避多包对单包充电的 风险，智能熔断器在 0.5 s 内可断开故障电流，可有效避免此类热失控发生。

关键词: 商用车；动力电池；电池包；热失控