Power hardware-in-the-loop (PHiL) simulations provide a powerful environment in the critical process of testing new components and controllers. In this work, we aim to explain the impact of time delays in a PHiL setup and recommend how to consider them in different investigations. The general concept of PHiL, with its necessary components, is explained and the benefits compared to pure simulation and implemented field tests are presented. An example for a flexible PHiL environment is shown in form of the Power Hardware-in-the-Loop Simulation Laboratory (PHiLsLab) at TU Hamburg. In the PHiLsLab, different hardware components are used as the simulator to provide a grid interface via an amplifier system, a real-time simulator by OPAL-RT, a programmable logic controller by Bachmann, and an M-DUINO microcontroller. Benefits and limitations of the different simulators are shown using case examples of conducted investigations. Essentially, all platforms prove to be appropriate and sufficiently powerful simulators, if the time constants and complexity of the investigated case fit the simulator performance. The communication interfaces used between simulator and amplifier system differ in communication speed and delay; therefore, they have to be considered to determine the level of dynamic interactions between the simulated rest of system and the hardware under test.

The significant increase of converter interfaced generation, consumption, storage, and transmission in power systems, results in the need to consider converter-driven stability in detail, as well as to study modelling and analysis methods with which such stability effects can be represented and investigated. Due to the multiple causes of converter-driven stability effects, a classification into further categories of fast and slow converter-driven stability is necessary, which is systematically presented in this paper. We further provide a detailed overview on appropriate modelling methods including static, quasi-dynamic and dynamic modelling and their respective applications. Typical analysis methods such as eigenvalue and impedance based analysis are explained and related to the previous modelling approaches. Based on that, a guide to which modelling and analysis method is appropriate for which type of converter-driven stability, is provided. In addition, open and recent research questions with regard to studies on nonlinear analyses of large systems with acceptable computational costs are pointed out.

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.

Low‐Voltage (LV) distribution grids are facing a rapid increase of connected Photovoltaic (PV) power plants as well as flexible consumers like Battery‐Electric Vehicle (BEV) chargers and Heat Pumps (HPs). The coordinated operation of these generation, storage and consumption units, referred to as Distributed Energy Resources (DERs), is regarded as a key requirement to maximize the benefits of renewable generation without violating, for example, voltage limits. Therefore, an operation management scheme was proposed in previous work that optimizes the power flows in LV grids in real‐time, where optimality is expressed as a maximization of the utility that DER owners experience from power consumption or injection, respectively. In this contribution, this method is extended by: (1) detailing a time‐varying utility‐model to express customer needs, (2) introducing a distributed implementation enhancing the robustness to failures, (3) developing a testbed using a real‐time digital power grid simulator and a communication network emulator, and (4) integrating a real‐time information flooding protocol. The performance is evaluated in different simulation scenarios, showing that the proposed method is able to cooperatively utilize the flexible units in order to fulfil the DER owners' needs even in the event of controller failures and constrained communication.

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.