STW participates in a fast-charging research project

Today’s public charging stations for electric vehicles have an average power of about 50 kW. In order to charge 80 percent of a 100 kWh battery, a typical size in larger cars, these charging stations need about 90 minutes. The research project "D-SEe" (Direct Superfast charging for Electric vehicles), funded by the Federal Ministry of Economic Affairs and Climate Action, has the goal of greatly accelerating this process. In the research project, leading industrial and electronics companies combine their expertise with that of the Forschungszentrum Jülich.

The result is a fast-charging station with 450 kW charging power and a prototype vehicle that remarkable in that it is close to being ready for series production. In combination, the technologies are able to charge the vehicle battery with the energy needed to drive 400 km in 15 minutes. To achieve this, the project partners have optimized the charging station, but above all the vehicle battery. In order to guarantee the fast-charging capability, appropriate cell technology has been used, along with a high-performance battery management system. This battery management system was developed by STW in Kaufbeuren.

The battery management system is based on the battery management kit mBMS.3 with the Aurix-based control platform from STW. It is supplemented with high-precision sensors for current and voltage monitoring (< 2 mV or 50 µΩ precision shunt) and other measurement components. The customized solution developed for this project provides a very high voltage level with which the required fast charging performance can be reached. It nevertheless complies with the international high-voltage standard EN IEC 60664 and common automotive standards and so represents a practical design.

The battery management kit mBMS.3 is the basis for future project-specific BMS solutions that must meet the highest demands for robustness, high-voltages and functional safety, while fulfilling all common standards for use on the road and in mobile machinery. STW will present the mBMS.3 at the bauma 2022 industrial trade fair in Munich.

For the battery management specialists at STW, the special challenge was the parallel development of the system with the vehicle. This is where the partnership approach of the automation specialists from Kaufbeuren came into play. In constant coordination with the other project partners and regular laboratory and test cycles, a high-performance solution was developed that is nevertheless close to a series product and makes a significant contribution to achieving the research project goals.