Christoph Molitor

Multiphysics Test Bed for Renewable Energy Systems in Smart Homes

This work introduces a multiphysics test bed which supports the testing of renewable energy systems in the context of home energy systems (HESs). The test bed, based on power-hardware-in-the-loop (PHIL) technology, allows for testing renewable energy systems and HESs in a holistic way. Homes, as the melting pot of different forms of energy, are one of the key enablers for the smart grid technology. The interface of different energy domains is the main propeller for innovation and development of new technologies. The test bed presented in this work comprises thermal, hydraulic, communication, and electrical interfaces, enabling a variety of testing scenarios. The modular structure of the test bed allows for a very flexible setup for analyzing different kinds of HESs.

New energy concepts and related information technologies: Dual Demand Side Management

This paper presents the concept of Dual Demand Side Management (2DSM) as an evolution of the conventional Demand Side Management concept. 2DSM accounts at the same time on one hand for the local needs, i.e. energy efficiency of the building stock as well as optimization of the local distribution grid and on the other hand for the challenges of the higher level electrical grid arising from the integration of renewable and alternative energy sources. The proposed concept shows the possibilities originating from the interaction of local district heating, heat storage and micro grid technology. Finally the paper shows the development and testing processes required for designing complex multi-domain systems.

MESCOS—A Multienergy System Cosimulator for City District Energy Systems

This work introduces a multidomain simulation platform that enables a holistic analysis of city district scale energy systems. The objective for the development of the simulation platform is to provide a tool that supports the design of control and energy management algorithms for those systems. The platform allows long-term simulations of a large number of buildings, including internal energy supply or energy conversion systems, in combination with external energy supply systems like the electrical grid. The simulation of those physical systems represents the environment for sophisticated control and energy management algorithms that can be tested on the platform. The concept of this work is to combine commercial-off-the-shelf software packages, here simulators and runtime infrastructure (RTI), to a high performance multidomain cosimulation platform. The high performance of the platform regarding computation time has been achieved by exploiting the parallel computing capabilities of modern simulation servers. Especially the computation time of large numbers of instances of Modelica-based models has been reduced significantly by the development of the parallel execution framework (PEF). The implementation of the PEF, including the interface to the individual models and to the RTI, is described in detail. The partitioning of the simulated system among different simulators does not influence the simulation results, as shown on the basis of a small-scale simulation scenario. The performance regarding the computation time is demonstrated on several example simulation scenarios showing the scalability of the platform.

Load Models for Home Energy System and micro grid simulations

The installation of Home Energy Systems will become more and more interesting for households or homes due to incentives for self-consumption of in-house generated power by photovoltaic systems or micro combined heat and power plants. The development of Home Energy Systems and residential micro grid concepts can be supported by simulations including detailed load models in order to investigate the efficiency of the applied energy management strategy or control strategy. This work presents a concept to generate realistic load models of individual homes with a high resolution, while reducing the required input information.

Consumer benefits of electricity-price-driven heat pump operation in future smart grids

This paper describes the financial benefits of consumers while applying different operating modes to their heat pump. In order to evaluate the different operating modes a single family house with heating system has been modeled and simulated with different operation strategies of the heating system and exposed to different electricity tariff schemes. Due to the detailed building model the comfort level resulting from the different operating modes has also been evaluated.

Decentralized coordination of the operation of residential heating units

This work presents an approach to decentralized coordination of electro-thermal heating systems, like Combined Heat and Power systems (CHP), Heat Pumps (HP), or Electric Heating systems (EH), each equipped with thermal storage, within a group or cluster of residential buildings. The flexibility of these thermal systems can be exploited for coordinating the heating units for a higher-level objective, like balancing power fluctuations of Renewable Energy Sources (RES). In order to assess the decentralized coordination algorithm (DCA) presented in this paper, its performance is compared with that of a centralized approach. In the centralized approach, a Mixed Integer Program (MIP) is formulated and solved, obtaining the optimal schedules for each heating system within the building cluster. In the decentralized approach, an MIP is first executed for each heating system, providing a set of schedules, which all satisfy the local constraints as well as local objectives of the building. Next, one schedule per set is selected in a way that the combination of the selected schedules facilitates the higher-level objective. The results presented in this work show that the proposed DCA can in principle balance power fluctuations as global objective, while still enabling local optimization. However, the results appear to be strongly dependent on the flexibility of the local optimization.

An advanced real-time simulation laboratory for future grid studies: Current state and future development

Power Grid is facing a tremendous change characterized by many challenges. Future grid will definitely be a complex system hard to study, analyze and design with traditional, analytical and rule based approaches. In this context it is clear that in the design of future smart-grid, simulation in support of design and Hardware In the Loop methods will have a key role. In this paper we present the actual structure of the Automation of Complex Power System laboratory and future planned expansion to support the development of new automation concepts for future smart grid.