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Item type:Publication, Access status: with files , Quantifying and optimizing the complexity: a comprehensive method to modeling and simulation in electrical DC systems : a maritime and mechatronic case study(2026); The development of maritime electrical energy systems is a key technology for greener shipping. In this work, a comprehensive methodology for creating models and simulations of electrical DC power systems to an appropriate level of accuracy is developed. The proposed methodology aims to optimize the simulation and model complexity a priori as to avoid an overly costly and excessively accurate simulation.Publicationtype: Doctoral Thesis78 38 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Access status: with files , Optimierung des Energiemanagements durch Aggregatoren(2025); In this work, a mixed-integer linear optimization model is developed to depict the decision-making problem of energy aggregators (EAs), which includes the deployment planning of various types of flexible energy resources and the trading of energy on different markets for a set of households assigned to the EA. The central research contribution compared to previous works in the development of the EA model (EAM) is that, on the one hand, it represents a holistic approach, as different types of energy resources and energy markets are integrated into the aggregated energy management of a community of households, and on the other hand, it features a high level of detail in the modeling of the technical restrictions of energy resources, in particular power-to-heat systems with heat pumps. In a case study with two seasonal scenarios, each consisting of 62 days, the EAM is verified and validated for day-ahead planning for up to 111 households. The results show that the participating households can achieve clear economic added value through the EA and that this added value is based on complex synergies between the system components, which can only be exploited through holistic and differentiated modeling. Further analyses consider an additional improvement in the efficiency of EA energy management through the foresighted use of energy storage systems. Standardized strategies are identified that contribute to an increase in household trading surpluses for different constellations of days. In addition, a fairness analysis is carried out, which shows that the internal trading between households depicted in the EAM is problematic in terms of fairness, as the flexibility provided to the community is not sufficiently rewarded. An ex-post redistribution of the realized community surpluses is proposed as an approach to improve fairness between households. Furthermore, the EAM is considered in the context of local energy markets. For this purpose, a model of a local market is developed that is integrated into a higher-level day-ahead process together with the EAM, thereby iteratively depicting local energy trading between EAs. Application in a case study shows that the composition of EAs' households has a strong influence on the resulting trading relationships. For example, specialization of EAs in specific types of households, resulting in heterogeneity among EAs, is advantageous in terms of local market efficiency compared to a set of unspecialized and thus homogeneous EAs, which, on the other hand, results in more internal energy exchange between the households of the respective EAs. In the case of a heterogeneous composition of EAs, a further study analyzes the possibility of targeted market interventions to reduce line congestion. A comparison of four different approaches, each with nine variants, leads to the conclusion that such a market-based approach can contribute positively to reducing line congestion, but that the potential is limited and the approaches presented should therefore be considered as supporting other congestion management tools. In conclusion, it is clear that EAs can play an important role in future energy systems by providing economically efficient energy management for households. The EAM developed in this thesis represents a basic model for depicting the decision-making problems of such energy management. There are many configuration options and influencing factors that must be taken into account for the successful application of the concept and the realization of the potential of EAs.Publicationtype: Doctoral Thesis71 36 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Access status: with files , Kategoriebasierte Lastprognose in Niederspannungsnetzen zur Day-Ahead-Koordinierung haushaltsnaher Flexibilität(2025)The increasing share of decentralized producers and flexible consumers complicates the maintenance of grid stability and raises the requirements for the control and monitoring of distribution networks. As part of a research project, a coordination function (COF) is being developed that performs day-ahead scheduling of flexible household loads to proactively prevent grid congestion. Since the schedule data of many households are incomplete, uncertainties arise in grid assessment and flexibility planning. This work addresses this issue and extends the existing concept by developing a forecasting method that provides the COF with a complete and reliable data basis. To this end, a data-driven approach is developed that applies the HDBSCAN clustering algorithm to categorize households with similar technical characteristics and consumption behavior, thereby forming representative load profiles. Missing schedules can thus be plausibly reconstructed. Subsequently, a gradient boosting regression refines the cluster-based forecasts by incorporating additional influencing factors such as weather, price, and grid data. The results demonstrate that the combination of clustering and regression analysis provides an effective approach for forecasting household schedules. This highly improves the data foundation for the COF and enables robust load forecasting even under limited data availability. The cluster forecast provides a high level of predictive accuracy at the aggregated level, while the regression analysis further improves accuracy at the household level. Individual households with highly specific consumption patterns can only be represented to a limited extent, which may affect the efficient use of flexibility in the grid but has only a minor impact on the overall reliability of the forecast. Future work should integrate real smart meter data to validate and improve the model quality and examine the use of deep learning-based methods to capture complex temporal patterns and short-term consumption changes even more accurately.Publicationtype: Master Thesis65 40 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Access status: with files , Entwicklung einer Methodik zur systemischen Optimierung elektrischer Antriebseinheiten durch weiterentwickelte Kühlkonzepte und antriebsinternes Thermomanagement(2023); The mobility sector is undergoing a radical change towards electromobility. This leads to increasing demands on the development of new electric powertrains of future electric vehicles. The electric drive unit should be cost-effective, compact, durable and be as effcient as possible in all driving scenarios under different environmental conditions. With increasing complexity and component integration of the drive units, the influence of the thermal behavior of the components (electric motor, power electronics and transmission) and their mutual coupling increases. Some of the components have strong divergent, optimal operating temperature ranges, which leads to opposite requirements for the drive unit cooling system. The cooling system and associated drive unit internal thermal management represent the interfaces between the components and offer additional possibilities to increase the effciency of the system. In order to develop the optimal overall concept of an electric drive unit for a vehicle platform, a systemic consideration of costs, effciency, mass and lifetime under compliance with installation space and limit temperatures for use in various vehicles is necessary. Within the scope of this thesis, a methodology for the systemic evaluation of cooling concepts and thermal management measures of electric drive units is developed. The components the tool chain (thermal component models, cost models and transmission design models) as well as the thermal drive model are validated on the basis of various different measurements. The presented tool chain enables the evaluation and optimization of cooling concepts for electric drive units under consideration of different drive cycles. In order to assess the overall system under the above aspects a cost equivalent number approach based on vehicle-speci c properties is used. Furthermore, additional drive unit internal thermal management measures are evaluated and optimized in order to reduce energy consumption and at the same time provide the best drive unit solutions. The application possibilities of the tool chain are shown based on various parameter studies and optimizations.Publicationtype: Doctoral Thesis320 193 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Access status: with files , Vergleichende Analyse von Software zur Modellierung von Energiesystemen mittels Integration in ein Framework zur Transformation(2022-01-31); The Tessif project, in the context of which this thesis was written, provides a software interface that enables an automated and standardized comparison of software for the modelling and optimization of energy supply systems. So far, Oemof and PyPSA are included and to which an energy system formulated in Tessif can be passed for optimization. The approach is based on two functions individually developed for the software model, to perform pre- and post-processing of all relevant components, parameters and data to realistically describe the energy system. Tessif is designed to compare the respective results, optimized with the same basis and to work out distinctive differences. The aim of this thesis is to integrate the software model FINE and to examine first results concerning an example energy system. The main task is to develop the individual functions for the automated transformation (es2es) as well as the standardized presentation of the results (es2mapping). Software for the optimization of energy systems usually makes use of five basic components (source, sink, energy conversion, storage and transmission). That serve to formulate and investigate a wide range of research topics. The intention of the translation is to automatically transform all components available in Tessif into the FINE specific interface and make them available for optimization. The second function to be developed enables the standardized presentation of the results. Relevant is detailed information about generation and load profiles, installed capacities as well as energy flow related emissions and costs. Finally, the total costs and emissions calculated during the optimization can be used as a basis for testing results of the respective software and making them initially comparable. In addition, a scenario analysis was carried out in this thesis, using an energy system specially developed for the comparison, in order to verify the function and results of FINE. Overall, it could be shown that the integration of FINE achieves approximately the same results as the integrations of Oemof and PyPSA and therefore is correctly integrated. Minor differences could be identified, analyzed and, if possible, adjusted to make the software models behave identically. In summary, initial results demonstrated that the capabilities of Tessif have been improved and, based on this, a recommendation can be formulated in the future to determine which software achieves the highest benefit in which scientific energy sector.Publicationtype: Master Thesis461 698 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Access status: without files , Lebenszyklus-orientierte Optimierung hybrider Brennstoffzellensysteme für LuftfahrtanwendungenPublicationtype: Doctoral Thesis73 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Access status: with files , Netzorientierter Betrieb von Batteriespeichersystemen in Verteilnetzen(2021-02-19); The change towards a more sustainable energy supply system requires the use of new technologies such as battery storage systems to support the power grid. This thesis develops a method for the simulative and experimental investigation of the operation of battery storage systems and for their technical and economical optimization . It appears that the combined provision of several services leads to an increase in profitability. In addition, it can be demonstrated experimentally in the laboratory that a reduction of the grid time constant can be compensated by using battery storage systems for frequency regulation.Publicationtype: Doctoral Thesis603 1820 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Access status: without files , 62 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Access status: with files , Load shaping of thermostatically controllable devices by constructing retail prices(2020); In the course of the energy transition the process of balancing power supply and demand becomes more challenging due to the uncertainty of renewable energy sources. Demand Response (DR) mechanisms encourage consumers to change their energy consumption, e.g. through time-varying electricity prices. This dissertation develops a price-based DR mechanism for cost-optimizing thermostatically controlled loads, which induces an aggregated load profile approximating a target schedule. A heuristic algorithm is developed to calculate suitable price signals. Simulations of realistic scenarios are analyzed to validate the functionality.Publicationtype: Doctoral Thesis329 788 - Some of the metrics are blocked by yourconsent settings
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