钠电池 PACK 的汇流排有什么作用？

What are the functions of busbars for sodium-ion battery PACK?

汇流排多为镀银铜、复合铝材质导电连接片，是 PACK 模组核心导电部件，承载三大不可替代核心功能。第一大功率电能传导：电芯之间依靠汇流完成串联、并联，承载充放电全回路电流，低阻抗材质降低传输压降与焦耳热损耗，提升整套 PACK 能量转换效率，大功率叉车、兆瓦级储能电站需加宽加厚汇流排适配大电流。第二模组结构机械固定：汇流排通过激光焊 / 螺栓锁紧电芯极柱，约束电芯相对位移，抵御运输颠簸、车辆行驶振动带来的电芯滑移，避免线束拉扯断裂。第三集成电压采样点位：汇流预留采样焊接端子，BMS 采集每一串单体实时电压，快速识别单串电芯压差过大、局部衰减故障，提前启动均衡或保护程序。汇流排表面需包裹绝缘热缩套管，杜绝相邻回路搭接短路，大功率 PACK 汇流排配套隔热垫片，焊接点位增加散热面积控制温升，是模组安全导电基础部件。

Busbars are conductive connecting sheets mostly made of silver-plated copper or composite aluminum, serving as core conductive components of PACK modules with three irreplaceable core functions. First, high-power electric energy transmission: cells realize series and parallel connection via busbars to carry full loop current during charging and discharging. Low-impedance materials reduce transmission voltage drop and Joule heat loss, improving the energy conversion efficiency of the whole PACK. Wide and thick busbars are adopted for high-power forklifts and megawatt-level energy storage power stations to adapt to large currents. Second, mechanical fixation of module structures: busbars lock cell terminals via laser welding or bolts to restrict relative cell displacement, resist cell sliding caused by transportation bumps and vehicle vibration, and prevent harness breakage from pulling. Third, integrated voltage sampling points: reserved sampling welding terminals on busbars enable BMS to collect real-time voltage of each single string, rapidly identify faults of excessive voltage difference and local attenuation of single cells, and activate balancing or protection procedures in advance. The surface of busbars shall be wrapped with insulating heat shrink tubes to avoid lap short circuits of adjacent loops. High-power PACK busbars are equipped with heat insulation gaskets, and welding points expand heat dissipation area to control temperature rise, acting as basic safe conductive components of modules.