Thermal Simulation of CCS Charging Inlet at High Charging Currents with Various Optimisation Approaches

Problem definition: Battery-electric commercial vehicles in particular have large battery capacities with several hundred kilowatt hours, some of which do not have enough energy for an entire working day, which is why they need to be recharged if necessary. High charging power with correspondingly high charging currents is required to recharge the electrical energy storage in an acceptable time. Due to the electrical losses, waste heat is generated, which places a thermal load on the charging components. In particular, the CCS charging inlet is subject to high thermal loads and, for safety reasons, must not exceed the maximum temperature of 90°C according to DIN EN IEC 62196-1. Depending on the ambient temperature, the charging inlet in the charging path often represents a thermally limiting component, as the charging current must be reduced before the maximum temperature is reached.

Solution: Three general solution approaches are used to investigate how the CCS charging inlet can be improved for the thermal challenge:

Objective: The CCS charging inlet is represented by a detailed Matlab thermal simulation model. A specific optimisation approach is derived for each of the three general solution approaches with the aim in the smallest possible component changes.

Target realisation: The general solution approach: “Heat reduction”, is investigated by the optimisation approach: “Reduction of contact resistance”. The general solution approach: “Heat absorption”, is investigated by the optimisation approach: “Increase of thermal mass”. The general solution approach: “Heat transmission”, is investigated by the optimisation approach: “Different insulator material”.

Finally, the thermal simulation of the CCS charging inlet shows the effects of all optimisation approaches together compared to the initial state.