Kinell’s new coupling system manages pre-charge and hot-plug disconnection for HVDC vehicle systems

Kinell, an engineering brand within the Fétis Group specialising in off-highway electrification, has launched an innovative high-voltage DC (HVDC) coupling system designed to facilitate safe and efficient connections and disconnections of external high-voltage components in electrified vehicles. This system allows for the integration of range extenders, swappable battery packs, or electrically powered implements without requiring modifications to the vehicle’s primary high-voltage architecture. By isolating all coupling functions into a dedicated subsystem, Kinell’s solution enables both the vehicle’s main HV system and the external device to remain largely unchanged, simplifying integration and reducing engineering complexity. The coupling unit itself incorporates a high-voltage interface box equipped with sensors and actuators, an integrated DC/DC converter to bridge different voltage levels, a safety coupling controller, and a physical connector with pull-off mechanisms and interlock pins for secure plug detection. Prior to connection, the system performs critical pre-connection checks such as isolation resistance measurement and connector presence verification, before managing pre-charging and voltage balancing between the two systems. During operation, it continuously monitors power flow and temperature, ensuring controlled disconnection and responding automatically to unintended plug removal or power overload situations. A key demonstration of the system’s capabilities is its deployment in a battery-electric MAN 4×4 truck used in agricultural and forestry applications. Here, external swappable battery packs connect via a standardised AEF/ISO 23316-2 high-power interface, effectively extending the truck’s operational range. The system supports hot-plug functionality, allowing batteries to be swapped while the vehicle continues running on its integrated packs, which Kinell describes as offering a rapid recharging solution without downtime. Dr Michael P. Schmitt, Managing Director of Kinell, emphasised the system’s main advantage as its ability to unify independent high-voltage systems into a single, safe, and efficient architecture through a self-contained solution that manages every aspect of the connection process. This development could have significant implications for the flexibility and scalability of electrified off-highway vehicles, potentially enabling more modular and adaptable powertrain configurations in future designs. Kinell’s coupling system represents a notable step forward in addressing the challenges of integrating external high-voltage components in electric vehicle platforms.