followed up

with Prof. Dr. Holger Borcherding (left), Ostwestfalen-Lippe University of Applied Sciences and Scientific Director of DC-Industrie2, and Dr. Hartwig Stammberger (right), Head of Digital Prototyping and Tools at Eaton and overall project manager of DC-Industrie2.

The DC-Industry project runs until September 2022. What milestones have been reached and what is still on your roadmap?

Stammberger : The DC-Industrie2 project is funded by the BMBF and supported by Project Management Jülich. Around 40 companies and research institutes from Germany are working closely together. A key milestone is the revision of the system concept and, in particular, the specification of the voltage ranges. Based on a technical report from the IEC (TR63282: "LVDC systems - Assessment of standard voltages and power quality requirements"), we have defined the voltage ranges in which a system can be operated for users and manufacturers. Furthermore, short-term deviations from the 600 to 750 V voltage range are permitted and it is described how the devices should behave in these time ranges.

The seven model systems at BMW, Homag, Kuka, Mercedes Benz and at the Ostwestfalen-Lippe University of Applied Sciences and the Fraunhofer Institutes IPA in Stuttgart and IISB in Erlangen will be equipped by the end of the year so that rigorous tests of the systems can then be carried out and evaluated in 2022.

One aspect of the DC industry is to create synergies with electromobility. What advantage does the industry see in this?

Borcherding: The big common ground is power electronics. Neither the DC industry nor electromobility is conceivable without power electronics. Germany's strength in power electronics must be expanded and can be a decisive factor in the implementation of future-oriented electrical systems.

Stammberger: Electromobility requires direct current in the vehicle, the batteries are operated with direct voltage and can simply be connected to the industrial DC grid for initial charging. Batteries can be used as storage and sources in the event of fluctuations in energy demand or supply. They can therefore ensure better energy quality and greater reliability.

In this context, how does the announcement by some OEMs that they will switch their production completely to electric vehicles by the 2030s affect your project?

Stammberger: This is a confirmation of the DC strategy. Electromobility is based on direct current; the charging infrastructure for the vehicles that will leave the factories can simply be connected to the DC industrial grid.

Borcherding: We have already designed DC industry for high power, distribution in a factory building and dynamic loads, as will be required for fast charging. In this sense, 'only' new dynamic loads would be added. We therefore see little technical impact at the moment. Charging electric vehicles is an additional argument for direct current grids and will accelerate development overall.

What impact will the intensified climate discussions in industry and society have on the project?

Borcherding: The energy transition and the climate crisis require a restructuring of the energy supply. The industry is intensively addressing the issues of energy transition, energy efficiency and sustainability. We have already demonstrated the advantages of direct current technology, which we were able to demonstrate in the DC industry projects, at various events such as the Hannover Messe or the SPS in Nuremberg. The advantages include the simple integration of solar energy, the reduction in connected load and the increased availability thanks to the simple connection of energy storage systems. These can also be used in other areas such as commercial, office and household applications. The task now is to make the enormous advantages of the DC grid visible to a wider audience. The transformation of the industry can only succeed with the support of business and politics.

Stammberger: The energy transition and the climate crisis require a restructuring of the energy supply. Some of the advantages of direct current technology that we were able to demonstrate in the DC industry projects - such as the simple integration of solar energy, the reduction in connected load, the use of braking energy and increased availability through the simple connection of energy storage systems - can also be used in other areas such as commercial, office and household applications.

Do you see comparable projects for office buildings in the future, e.g. for operating server systems and the like?

Borcherding: DC technology will grow strongly in many areas. Even today, the internal power distribution of new server systems can hardly manage without direct current. In office buildings, the infrastructure is the lever. As soon as air conditioning is an issue, i.e. electric drives are used, and solar energy generation on the building is feasible, DC technologies are advantageous.

Stammberger: There are several projects for office applications and, with the Brainergy Park in Jülich, a specific publicly funded application for commercial and office use. The main aim now is to make it easy for users and appliance manufacturers to exploit the benefits of DC technology. To this end, the project partners are already active in standardization and we are working together with the ZVEI on the preparation of a DC alliance to further develop DC technology beyond the existing research projects and to inform the market in the long term.