The intermittent energy supply from distributed resources and the coupling of different energy and application sectors play an important role for future energy systems. Novel operational concepts require the use of widespread and reliable Information and Communication Technology (ICT). This paper presents the approach of a research project that focuses on the development of an innovative operational concept for a Smart Integrated Energy System (SIES), which consists of a physical architecture, ICT and energy management strategies. The cellular approach provides the architecture of the physical system in combination with Transactive Control (TC) as the system’s energy management framework. Independent dynamic models for each component, the physical and digital system, operational management and market are suggested and combined in a newly introduced co-simulation platform to create a holistic model of the integrated energy system. To verify the effectiveness of the operational concept, energy system scenarios are derived and evaluation criteria are suggested which can be employed to evaluate the future system operations.

The TransiEnt Library is an open-source Modelica Libraryoriginally developed at the Hamburg University ofTechnology. It is a flexible framework for modelling andanalysing the dynamic behaviour of coupled energy systemsunder current and future scenarios. With the addition ofthree new members to the TransiEnt Library consortium,namely Fraunhofer UMSICHT, Gas- und Wärme-InstitutEssen~e.V. and XRG Simulation GmbH, the TransiEnt Libraryhas expanded its portfolio of models and methods forinvestigating the challenges in energy systems. Buildingupon the previous status report, this article presents thelatest developments in the TransiEnt library, highlithingits extended capabilities to model and simulate large,complex energy systems. The recent developments include theautomatic generation of aggregated models at district andregionals levels, as well as the modelling of medium- andlow-voltage electrical distribution networks. In addition,new concepts for the representation of large-scale heatingnetworks have been developed and are presented alongsideillustrative use cases.

The energy transition has recently experienced a further acceleration. In order to make the integration of renewable energies as cost-effective, secure and sustainable as possible and to develop new paradigms for the energy system, many energy system models have been developed in research in the past to evaluate the solutions. While model identification and dissemination of results are widely discussed in the literature, a detailed view of the methodology is often missing. This paper addresses this topic and proposes a methodology to build a comprehensive, publicly accessible database for modeling a multi-modal integrated energy system. The focus hereby is dynamic modeling of low- and medium-voltage grids consisting of prosumers, battery storages, heat pumps and electric cars. In addition, a district heating network is parameterized to match the electricity grid. Modelica and the TransiEnt-Library serves as the modeling tool. The methodology for creating the grid models is available via GitLab. A study case that uses the methodology to analyze the congestion situation within a medium-voltage distribution grid is presented.

Future energy systems rely mostly on supply-dependent resources like wind and solar energy. Since most of the produced energy from distributed renewable sources arises as electricity, electrification of energy consumers and producers, called prosumers, expands. In this context, multi-modal distribution grids make use of the storage capabilities of other energy sectors like heat, and abolish the supply-dependency and uncertainty of the feed-in of decentralized generators. This provides flexibility in the energy system, which increases security of supply and at the same time ensures economical energy provision. The subject of this paper is to exploit the flexibility of such a multi-modal energy system for operation in an optimal way. The cellular approach serves here as the energy system architecture. Aim is to provide flexibility with a cell by optimally distributing a flexibility request to subordinate prosumers changing their active and reactive power. The load change is hereby to be optimally dispatched to the different components of the prosumers under consideration of technical restrictions and dynamic behavior of components, the grids and economical aspects. For dynamic modelling and simulation the open-source modelling language Modelica is used. Using a low-voltage benchmark model expanded by multi-modal technologies, the proposed methodology shows that the cells are capable of providing flexibility to the overlying grid with high accuracy at low costs.