TY - CHAP A1 - Hahn, Christoph A1 - Burkhardt, Matthias A1 - Semerow, Anatoli A1 - Luther, Matthias A1 - Ruhle, Olaf T1 - Generic modeling of a self-commutated multilevel VSC HVDC system for power system stability studies T2 - 2015 IEEE Applied Power Electronics Conference and Exposition N2 - This paper provides a generic stability model of a self-commutated multilevel VSC (Voltage Source Converter) HVDC (High Voltage Direct Current) and its appropriate control. At first the approach of modeling depicts the independence of the AC and DC quantities and therefore two separate models - one for the AC and one for the DC side - can be figured out. The AC side model is developed in the dq frame out of the according differential equations. For the DC side no further transformation is required. Regarding the fact of balanced energy terms the two models can be merged. The consolidation of both models reveals a comprehensive large signal model of a multilevel based HVDC system which can be used for detailed analyses in power system stability studies. Due to the comparison of the generic stability model with an EMT (Electro-Magnetic Transient) HVDC model the consistence of the dynamic behavior is shown. Y1 - 2015 SN - 978-1-4799-6735-3 U6 - https://doi.org/10.1109/apec.2015.7104728 PB - IEEE Computer Society Press ER - TY - CHAP A1 - Hahn, Christoph A1 - Semerow, Anatoli A1 - Luther, Matthias A1 - Ruhle, Olaf T1 - Generic modeling of a line commutated HVDC system for power system stability studies T2 - Proceedings of the IEEE Power Engineering Society Transmission and Distribution Conference N2 - This paper will reveal a novel comprehensive approach for generic modeling and control design of line commutated HVDC systems. The model will be developed based on the essential HVDC equations and transfer functions. Due to comparing the generic model with an EMT (Electro-Magnetic Transient) HVDC model the consistence of the dynamic behavior will be shown. Furthermore modeling of additional HVDC system facilities like transformer tap-changers and AC filters will be annotated. Control design schemes for line commutated HVDC systems will be derived and the interactions of the controllers applied to the developed model will be investigated. © 2014 IEEE. Y1 - 2014 SN - 978-1-4799-3655-7 U6 - https://doi.org/10.1109/TDC.2014.6863308 PB - Institute of Electrical and Electronics Engineers ER - TY - JOUR A1 - Gensler, Marius A1 - Malkmus, Christoph A1 - Ockermann, Philipp A1 - Möllmann, Marc A1 - Hahn, Lukas A1 - Salehi, Sahar A1 - Luxenhofer, Robert A1 - Boccaccini, Aldo R. A1 - Hansmann, Jan T1 - Perfusable Tissue Bioprinted into a 3D-Printed Tailored Bioreactor System JF - Bioengineering N2 - Bioprinting provides a powerful tool for regenerative medicine, as it allows tissue construction with a patient’s specific geometry. However, tissue culture and maturation, commonly supported by dynamic bioreactors, are needed. We designed a workflow that creates an implant-specific bioreactor system, which is easily producible and customizable and supports cell cultivation and tissue maturation. First, a bioreactor was designed and different tissue geometries were simulated regarding shear stress and nutrient distribution to match cell culture requirements. These tissues were then directly bioprinted into the 3D-printed bioreactor. To prove the ability of cell maintenance, C2C12 cells in two bioinks were printed into the system and successfully cultured for two weeks. Next, human mesenchymal stem cells (hMSCs) were successfully differentiated toward an adipocyte lineage. As the last step of the presented strategy, we developed a prototype of an automated mobile docking station for the bioreactor. Overall, we present an open-source bioreactor system that is adaptable to a wound-specific geometry and allows cell culture and differentiation. This interdisciplinary roadmap is intended to close the gap between the lab and clinic and to integrate novel 3D-printing technologies for regenerative medicine. Y1 - 2024 U6 - https://doi.org/10.3390/bioengineering11010068 SN - 2306-5354 VL - 11 IS - 1 PB - MDPI ER -