High voltage distribution units for Rosenbauer
SUNCAR and Rosenbauer develop high voltage distribution units for the fully electric PANTHER electric airport firefighting vehicle
As part of a multi-year development project, SUNCAR AG has worked closely with Rosenbauer International AG to develop the high-voltage distribution units for the new PANTHER electric – the first fully electric airport firefighting vehicle in the renowned PANTHER series.
Basics and project structure
Initial acquisition talks were held in the early project phase at the beginning of 2022. Detailed audits were carried out prior to commissioning in order to precisely identify the technical and regulatory requirements of the various target markets. On this basis, robust specifications and sound contractual foundations were developed in collaboration, enabling structured and targeted project management.
Development followed proven automotive processes and international standards. Validation, documentation, and quality assurance were implemented in accordance with established standards to ensure the system's suitability for series production.
Scope of services: Development and series production of HVDUs
A central component of the high voltage system are the energy distribution units for high-voltage technology (HVDUs) and DC fast charging, developed by SUNCAR. SUNCAR was responsible for both the customer-specific development and series production of these systems. Each vehicle has a total of six HVDUs: two main HVDUs (MAIN), two for power supply (PS), and two auxiliary (AUX) HVDUs. All units are designed for voltages up to 1000 VDC to ensure maximum performance and operational safety in use.
The main HVDU is equipped with two powerful DC contactors that enable safe disconnection and switching of the batteries as well as reliable supply to the drive systems. An integrated insulation monitor further increases safety, while all connectors are integrated into the safety circuit (interlock). Additional safety features such as short-circuit brackets underline the high quality and safety standards.
The design of the AUX and PS HVDUs was implemented particularly efficiently: both types are based on the same platform, which reduced the number of variants and lowered production costs without compromising functionality.
The HVDUs meet the highest requirements in terms of service life and operational availability. Extensive thermal stress tests were carried out both internally and in external laboratories to ensure reliability under various load conditions at inputs and outputs. The HVDUs withstand temperatures from –40 °C to +60 °C, are rated according to water and dust protection class IP67 / IP6K9K, and are functional at altitudes from –80 to 4,000 m. In addition, short-circuit tests with currents above 18 kA were successfully completed.
Each vehicle is also equipped with two standard INTERFLOW500 DC fast-charging interfaces from SUNCAR and charging controllers with CCS communication. The same high requirements apply here as for the customer-specific high-voltage distribution units.
SUNCAR's energy distribution units were designed for the extreme demands of an emergency vehicle with 1200 hp and a top speed of 120 km/h. The PANTHER 6x6 accelerates from 0 to 80 km/h in up to 25 seconds in pure electric mode. Boost mode, in which additional electrical drive energy is provided by an EnergyBackupSystem installed in the vehicle, enables the PANTHER electric to accelerate from 0 to 80 km/h in less than 20 seconds. Power is supplied by HV batteries with a nominal energy content of 256 kWh, supplemented by an EnergyBackupSystem for maximum operational flexibility. The system also supports a maximum charging power of 250 to 300 kW (DC). This means that the energy required for a typical use of this vehicle at the airport can be provided in approximately 20 minutes.
Global series production and target markets
In addition to the high technical requirements, the international nature of the project added an extra layer of complexity. Together with numerous partners, a global supply chain was established that meets both worldwide series production and country-specific requirements, with a focus on the US market. The main target markets for the PANTHER electric are Europe, the US, and Asia, where the diesel-powered series is already successfully in use in over 100 countries in what is now its fourth generation.
