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S. Rohjans

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11 records found

Journal article (2018) - C. Steinbrink, A.A. van der Meer, M. Cvetkovic, D. Babazadeh, S. Rohjans, P. Palensky, S. Lehnhoff
Evaluating new technological developments for energy systems is becoming more and more complex. The overall application environment is a continuously growing and interconnected cyber-physical system so that analytical assessment is practically impossible to realize. Consequently, new solutions must be evaluated in simulation studies. Due to the interdisciplinarity of the simulation scenarios, various heterogeneous tools must be connected. This approach is known as co-simulation. During the last years, different approaches have been developed or adapted for applications in energy systems. In this paper, two co-simulation approaches are compared that follow generic, versatile concepts. The tool mosaik, which has been explicitly developed for the purpose of co-simulation in complex energy systems, is compared to the High Level Architecture (HLA), which possesses a domain-independent scope but is often employed in the energy domain. The comparison is twofold, considering the tools’ conceptual architectures as well as results from the simulation of representative test cases. It suggests that mosaik may be the better choice for entry-level, prototypical co-simulation while HLA is more suited for complex and extensive studies. ...
Conference paper (2017) - A.A. van der Meer, P. Palensky, T.I. Strasser, V. H. Nguyen, N. Akroud, M.H. Syed, A. Emhemed, S. Rohjans, R. Brandl, A.M. Khavari, K. Heussen, D.E. Morales Bondy, O. Gehrke, C. Steinbrink, M. Blank, S. Lehnhoff, E. Widl, C. Moyo
The gradual deployment of intelligent and coordinated devices in the electrical power system needs careful investigation of the interactions between the various domains involved. Especially due to the coupling between ICT and power systems a holistic approach for testing and validating is required. Taking existing (quasi-) standardised smart grid system and test specification methods as a starting point, we are developing a holistic testing and validation approach that allows a very flexible way of assessing the system level aspects by various types of experiments (including virtual, real, and mixed lab settings). This paper describes the formal holistic test case specification method and applies it to a particular co-simulation experimental setup. The various building blocks of such a simulation (i.e., FMI, mosaik, domain-specific simulation federates) are covered in more detail. The presented method addresses most modeling and specification challenges in cyber-physical energy systems and is extensible for future additions such as uncertainty quantification. ...
Conference paper (2017) - Panos Kotsampopoulos, Nikos Hatziargyriou, K. Heussen, Mihai Calin, A. Khavari, M. Sosnina, J. E. Rodriguez, G. M. Burt, T. I. Strasser, Cyndi Moyo, Sebastian Rohjans, C Steinbrink, Sebastian Lehnhoff, P. Palensky, A. A. van der Meer, D. E. Morales Bondy
Traditional power systems education and training is flanked by the demand for coping with the rising complexity of energy systems, like the integration of renewable and distributed generation, communication, control and information technology. A broad understanding of these topics by the current/future researchers and engineers is becoming more and more necessary. This paper identifies educational and training needs addressing the higher complexity of intelligent energy systems. Education needs and requirements are discussed, such as the development of systems-oriented skills and cross-disciplinary learning. Education and training possibilities and necessary tools are described focusing on classroom but also on laboratory-based learning methods. In this context, experiences of using notebooks, co-simulation approaches, hardware-in-the-loop methods and remote labs experiments are discussed. ...
Conference paper (2017) - T. I. Strasser, Cyndi Moyo, J. Merino, C. Sandroni, Maurizio Verga, Mihai Calin, A. Khavari, M. Sosnina, E. de Jong, Sebastian Rohjans, A. Kulmala, K. Mäki, Roland Bründlinger, R. Brandl, Federico Coffele, G. M. Burt, Panos Kotsampopoulos, Nikos Hatziargyriou, S Lehnhoff, M. Blank, P. Palensky, A. A. van der Meer, K. Heussen, Oliver Gehrke, J. E. Rodriguez
Renewables are key enablers in the plight to reduce greenhouse gas emissions and cope with anthropogenic global warming. The intermittent nature and limited storage capabilities of renewables culminate in new challenges that power system operators have to deal with in order to regulate power quality and ensure security of supply. At the same time, the increased availability of advanced automation and communication technologies provides new opportunities for the derivation of intelligent solutions to tackle the challenges. Previous work has shown various new methods of operating highly interconnected power grids, and their corresponding components, in a more effective way. As a consequence of these developments, the traditional power system is being transformed into a cyber-physical energy system, a smart grid. Previous and ongoing research have tended to mainly focus on how specific aspects of smart grids can be validated, but until there exists no integrated approach for the analysis and evaluation of complex cyber-physical systems configurations. This paper introduces integrated research infrastructure that provides methods and tools for validating smart grid systems in a holistic, cyber-physical manner. The corresponding concepts are currently being developed further in the European project ERIGrid. ...
Conference paper (2017) - C Steinbrink, S Lehnhoff, A. A. van der Meer, K. Heussen, Oliver Gehrke, E. Guillo-Sansano, M. H. Syed, A. Emhemed, R. Brandl, V. H. Nguyen, A. Khavari, Q. T. Tran, Sebastian Rohjans, Panos Kotsampopoulos, Nikos Hatziargyriou, N. Akroud, E. Rikos, M. Z. Degefa, T. I. Strasser, Edmund Widl, Cyndi Moyo, Georg Lauss, F. Lehfuss, M. Faschang, P. Palensky
Smart grid systems are characterized by high complexity due to interactions between a traditional passive network and active power electronic components, coupled using communication links. Additionally, automation and information technology plays an important role in order to operate and optimize such cyber-physical energy systems with a high(er) penetration of fluctuating renewable generation and controllable loads. As a result of these developments the validation on the system level becomes much more important during the whole engineering and deployment process, today. In earlier development stages and for larger system configurations laboratory-based testing is not always an option. Due to recent developments, simulation-based approaches are now an appropriate tool to support the development, implementation, and roll-out of smart grid solutions. This paper discusses the current state of simulation-based approaches and outlines the necessary future research and development directions in the domain of power and energy systems. ...

An overview and discussion of different possibilities

Journal article (2016) - Thomas Strasser, Filip Pröstl Andrén, Panos Kotsampopoulos, Nikos Hatziargyriou, Gunter Arnold, Wolfram Heckmann, Erik Jong, Maurizio Verga, Giorgio Franchioni, Luciano Martini, Anna Kosek, Oliver Gehrke, Georg Lauss, Henrik Bindner, Federico Coffele, Graeme Burt, Mihai Calin, Emilio Rodriguez-Seco, Roland Bründlinger, Helfried Brunner, Cyndi Moyo, Christian Seitl, Sebastian Rohjans, Sebastian Lehnhoff, Peter Palensky
Renewable energy sources are key enablers to decrease greenhouse gas emissions and to cope with the anthropogenic global warming. Their intermittent behaviour and limited storage capabilities present challenges to power system operators in maintaining the high level of power quality and reliability. However, the increased availability of advanced automation and communication technologies has provided new intelligent solutions to face these challenges. Previous work has presented various new methods to operate highly interconnected power grids with corresponding components in a more effective way. As a consequence of these developments the traditional power system is transformed into a cyber-physical system, a smart grid.
Previous and ongoing research activities have mainly focused on validating certain aspects of smart grids, but until now no integrated approach for analysing and evaluating complex configurations in a cyber-physical systems manner is available. This paper tackles this issue and addresses system validation approaches for smart grids. Different approaches for different stages in the design, development, and roll-out phase of smart grid solutions and components are discussed. Finally, future research directions are analysed. ...