Research Projects

Multi-terminal direct current (MTDC) systems appear to be one of the most promising technologies for transmitting large power over long distances using cables and/or overhead lines. MTDC structures are therefore expected in future energy systems in Europe and Japan, but also in other parts of the world, in order to be able to implement the politically and socially set goals of further integration of renewable generation plants as well as to enable or expand power exchanges between neighboring market areas for economic and technical reasons.

In contrast, there is only a very limited amount of experience available in the operation of combined or meshed AC/DC systems, especially with simultaneous DC-side meshed systems. The same applies to the availability of appropriate simulation environments for stability analysis and optimization of corresponding network structures. Approaches for the development of methods for the evaluation of the influence on grid stability and optimization potentials of corresponding algorithms for the optimized resolution of grid bottlenecks have been developed and verified on extended transmission systems. Furthermore, aggregated balance models exist which allow an evaluation of different behaviors of generation types and can show their influence on the frequency/efficiency behavior of corresponding systems.

Publications

1. Naoki Kawamoto, Yoshihiko Susuki, Salvatore D’Arco, Atsushi Ishigame, Denis Mende, David Sebastian Stock: ‚Load Margin for Short-term Voltage Stability of an Interconnected AC/MTDC System‘, Nonlinear Theory and Its Applications (NOLTA), IEICE, Vol. 12, Nr. 4, 2021. Online:  https://www.jstage.jst.go.jp/article/nolta/12/4/12_711/_article
   
   
2. Naoki Kawamoto, Yoshihiko Susuki, Atsushi Ishigame, Tsuyoshi Funaki, Salvatore D’Arco, Denis Mende, David Sebastian Stock: ‚Modular modeling for large-signal simulations of a multi-machine AC grid with MTDC interconnection‘, The Institute of Electrical Engineers of Japan: Annual Meeting of the Electric Power and Energy Division (IEEJ PES), 2020.
   
   
3. Denis Mende, David Sebastian Stock, Lutz Hofmann: ‚Implementation, Verification and Application Examples of a Mathematical Optimization for Grid Operation in Mixed AC/DC-Systems‘, CIGRÉ International Symposium 2019, Aalborg, 2019.
   
   
4. Denis Mende, Holger Becker, David Sebastian Stock, Walter Schittek, Lutz Hofmann: ‚Modelle zur Analyse des Frequenzverhaltens ausgedehnter Übertragungssysteme’, 15. Symposium Energieinnovation, Graz, 2018. Online: https://www.tugraz.at/fileadmin/user_upload/Events/Eninnov2018/files/kf/Session_D4/KF_Mende.pdf