How does a copper busbar handle the temperature rise caused by instantaneous high current in fast charging scenarios?
Publish Time: 2025-12-08
With the rapid development of fast charging technology for electric vehicles, the copper busbar, a key conductive component in the battery system, needs to effectively control temperature rise under the impact of instantaneous high current to ensure the safe, stable, and long-term reliable operation of the power distribution unit and battery isolation unit. As a core power transmission channel, the design of the copper busbar no longer focuses solely on conductivity but also requires comprehensive consideration of thermal management, structural optimization, and materials science.
Our copper busbar products are meticulously developed for this demanding application scenario. Through systematic engineering design, we have successfully achieved effective suppression of temperature rise under high-power fast charging conditions, fully meeting the high standards of performance, safety, and reliability required by modern EVs and energy storage systems.
1. High-purity oxygen-free copper: Laying the foundation for low impedance
The fundamental source of temperature rise is Joule heating, where resistance R is a key variable. We use high-purity oxygen-free copper as the busbar substrate, significantly lower than ordinary industrial copper. Lower resistance means less heat is generated under the same current, suppressing temperature rise at its source. Meanwhile, oxygen-free copper exhibits superior ductility and creep resistance, maintaining structural integrity during long-term thermal cycling and preventing increased contact resistance due to microcracks.
2. Cross-section and Topology Optimization: Enhancing Current Carrying and Heat Dissipation Efficiency
We don't simply increase the amount of copper used; instead, we achieve uniform current density distribution within a limited space through simulation-driven cross-section and 3D topology optimization. For example, a widened, flat cross-section design not only increases the conductor surface area to enhance natural convection heat dissipation but also reduces the skin effect. Local thickening or chamfering in areas of concentrated current prevents hotspot formation. Furthermore, some products incorporate microchannel or heat dissipation fin structures, working in conjunction with the battery pack cooling system to achieve active thermal management.
Inside the PDU/BDU, the interface contact resistance between the copper busbar and components such as relays, fuses, and connectors has a significant impact on the overall temperature rise. We apply precision plating treatments—such as silver or tin plating—to critical contact surfaces, significantly reducing contact resistance and effectively preventing copper oxidation in high-temperature and high-humidity environments. A stable, low-resistance connection ensures that the connector will not become a "thermal bottleneck" even at fast charging rates above 3C.
4. Integrated and Modular Design: Adapting to High-Voltage Platform Requirements
For 800V high-voltage fast charging platforms, our copper busbar employs integrated stamping and laser welding processes, reducing traditional bolt connections and thus lowering failure rates and parasitic resistance. The modular design also supports rapid assembly and maintenance, while electromagnetic compatibility optimization reduces magnetic field interference from high-current loops, improving overall system safety.
At this crucial juncture as electric mobility moves towards the ultra-fast charging era, the copper busbar has evolved from a "passive conductor" to an "active thermoelectric management unit." Through deep integration of materials, structure, processes, and system integration, we have created a copper busbar solution that combines high conductivity, strong heat dissipation, and high reliability, providing solid support for the efficient and safe operation of electric vehicles and energy storage systems—ensuring rock-solid stability for every fast charge.
