Preamble and goals

The KDEE

The Competence Center for Decentralized Electrical Energy Supply Technology (KDEE) at the University of Kassel was inaugurated in 2008 by Minister Kühne-Hörmann (CDU) and established as a separate structural unit of the University in January 2009. Since then, a joint development initially took place with the Department of Electrical Power Systems (todays department of Power Electronics). This development was complemented with the appointment of Prof. Dr.-Ing. Martin Braun in 2012 with the department 'Energy Management and Operation of Electrical Networks' (e²n) and in 2015 with Prof. Dr.-Ing. Albert Claudi (Department of Systems and High Voltage Engineering, AHT) and Prof. Dr. rer. nat. Clemens Hoffmann (Department of Integrated Energy Systems, INES) to strengthen the research focus on energy systems engineering in Northern Hesse.

The topics "use of renewable energy sources" and "conservation of resources by increasing efficiency" are more topical than ever. Decarbonization, decentralization and digitalization are driving forces in the transformation of energy systems.

New objectives

Originally, the focus of interest in the use of renewable energy sources was the provision of active power with maximum efficiency. Many systems engineering issues are now being added. Grids that were dominated by large electrical machines are becoming grids that are increasingly characterized by power electronic energy converters and volatile energy flows. The higher the share of volatile generators in the total installed power, the more questions about securing the stability and quality of the grids come to the fore. Here, the KDEE sees future-proof tasks in the design of the technical system through the development of actuators, suitable automation technology and a set of rules for the interaction of the networked energy technology components.

Up to 2010, the addition of decentralized electrical energy generators could hardly have any real negative effects due to the still relatively small share in area-wide distribution. Due to the high growth rate in the addition of decentralized energy feeders, this situation has changed fundamentally. The consideration of cumulative values, which is often carried out in public, does not lead to sensible solutions here in individual cases. Consumption and feed-in of energy into the electrical grid are largely uncorrelated, both spatially and temporally. At the same time, the interconnected grid is not a "short copper plate", but forms an "areal" elastic system with a horizontal extension of several 1000 km. There is also an additional "vertical" extension due to the local hierarchical ordering of the transmission and distribution networks into different voltage levels, each with its own network topology.

Further expansion requires system knowledge and coordination. The KDEE sees itself as responsible for this, from the side of basic research to the development of new principle solutions for actuators and system components to questions of grid control, quality assurance and thus the technical and economic optimization of the design and control of decentralized energy systems.

Further research

In the context of digitalization, open source, platforms and artificial intelligence play an important role, which is also a focus at KDEE. At the KDEE, together with Fraunhofer IEE, pandapower (www.pandapower.org), a now widely used new open source platform for grid calculations and grid optimization, was developed, thus laying a foundation for various software solutions for grid analysis and grid optimization. The increasingly relevant platform idea is also continued by the co-simulation environment OpSim (www.opsim.net) for the analysis of the interaction of software components in complex power systems. In addition to classical methods of optimization, artificial intelligence methods are also being further developed for numerous areas of electrical grids (e.g., modeling, analysis, state estimation, planning, operations management).

The quest for energy conversion with maximum efficiency to reduce CO2 emissions and lower costs is increasingly transferring from the field of renewable energy technology to other areas. In addition to heat supply through cogeneration and heat pumps, another important example is automotive engineering - with or without electric drive. Avoided losses mean avoided expenditures for cooling, lower mass and longer ranges. To advance this development, the KDEE and its departments are also simultaneously involved in the Vehicle Systems Research Network (FAST) at the University of Kassel. Energy savings also lead to cost advantages in industrial automation, lighting technology and medical technology, so that further "spin offs" of previous research activities can be expected here.

The clearly discernible trend that for some years now there has been an increasing number of people interested in studying energy technology is very encouraging. The trend of leading a noticeably higher proportion than in the past to a master's degree should also be emphasized at this point. The KDEE offers courses on a wide range of classic and new energy technology topics in order to ensure that the next generation of students will be able to design the energy supply systems of the future.

It was therefore a far-sighted decision by the State of Hesse through the Hessian Ministry of Science and Art, together with the University of Kassel, to expand science and research in these areas through funding and close cooperative relationships with industry.

Integration into Kassel's research community

The KDEE is linked to the Fraunhofer IEE in a close cooperation through personnel linkage of the departments e²n and INES, so that the competences of the leading regional research institutions in the subject area of decentralized electrical energy supply can be optimally coordinated in order to jointly advance the energy turnaround in North Hesse, nationally and internationally with this location strength.

The staff and students of KDEE are committed to further strengthening the cooperation of the University of Kassel with other scientific institutions such as Fraunhofer IEE and business partners, as well as the international visibility of its capabilities in the field of sustainable energy supply, and sincerely thank their sponsors and cooperation partners.

• Research and development of new system elements and structures for the decentralized provision of electrical energy in a public supply system, both interconnected and in isolated island networks.
• Development of basic solutions for devices, plants and systems for the decentralized provision of electricity and heat for the effective use of all economically viable energy resources
• Research and development of concepts and technical solutions for integrated solutions for the simultaneous use of different energy resources in combined heat and power plants, PV solar plants, fuel cells with and without storage integration
• Control and operational management of networked energy suppliers and energy storage systems in mobile systems and on-board networks
• Training of highly qualified engineers with a doctorate in energy technology.