@inproceedings{SchweibererRauchBrueckl, author = {Schweiberer, Philipp and Rauch, Johannes and Br{\"u}ckl, Oliver}, title = {Long-term analysis of industrial reactive power potentials with consideration of plant-internal grid restrictions using the example of an industrial plant in a distribution grid}, series = {NEIS 2022; Conference on Sustainable Energy Supply and Energy Storage Systems, 26-27 September 2022, Hamburg}, booktitle = {NEIS 2022; Conference on Sustainable Energy Supply and Energy Storage Systems, 26-27 September 2022, Hamburg}, editor = {Schulz, Detlef}, publisher = {VDE-Verlag}, address = {Berlin}, isbn = {978-3-8007-5983-5}, issn = {2510-6902}, pages = {51 -- 56}, abstract = {Since conventional generation plants provide a considerable share of reactive power but are gradually being shut down due to energy transition, leading to power deficits at the transmission grid level, new concepts for the supply of reactive power must be developed. As one possibility for the latter, industrial plants in the distribution grid are considered suitable, as their reactive power potentials can contribute to voltage maintenance and thus to a grid- or system-serving behavior. In this paper, the determination of reactive power potentials provided by industrial compensation systems (ICS) is presented. An industrial plant in the medium voltage grid, with three installed ICSs, is investigated. The potentials are determined and described based on their time characteristics, which provide information about the occurrence and distribution of inductive and capacitive potentials. A grid simulation of the investigated industrial grid is used to analyze the effects of retrieving the reactive power potentials regarding equipment utilizations and voltage limits.}, language = {en} } @misc{ReindlErikssonNiemetzetal., author = {Reindl, Andrea and Eriksson, Lars and Niemetz, Michael and Sangyoung, Park and Meier, Hans}, title = {Control Concepts for a Decentralized Battery Management System Decentralized Battery Management System Global Control Level}, series = {16th International Renewable Energy Storage Conference (IRES2022), 20 to 22 September 2022, D{\"u}sseldorf}, journal = {16th International Renewable Energy Storage Conference (IRES2022), 20 to 22 September 2022, D{\"u}sseldorf}, publisher = {Eurosolar}, language = {en} } @inproceedings{KoernerReindlMeieretal., author = {K{\"o}rner, Patrick and Reindl, Andrea and Meier, Hans and Niemetz, Michael}, title = {A Theoretical Comparison of Different Virtual Synchronous Generator Implementations on Inverters}, series = {2022 24th European Conference on Power Electronics and Applications (EPE'22 ECCE Europe): 05-09 September 2022, Hannover, Germany}, booktitle = {2022 24th European Conference on Power Electronics and Applications (EPE'22 ECCE Europe): 05-09 September 2022, Hannover, Germany}, publisher = {IEEE}, pages = {9}, abstract = {The goal to overcome the global climate crisis leads to a rising demand for the usage of Renewable Energy Sources (RES). Decentralized control strategies are needed to allow the integration of RES into the grid. The Virtual Synchronous Generator (VSG) is proposed as a method to add virtual inertia to the grid by emulating the rotating mass of a Synchronous Generator (SG) on the control algorithm of an inverter. This paper presents the VSG control structure as well as the mathematical description in a unified form. Due to the fact that classical droop control can be seen as a special form of the VSG, their correlation is highlighted by evaluating the steady state output characteristics of the inverter. Furthermore, a theoretical comparison between different VSG topologies, including the VISMA-Method 2 and the synchronverter, is given. In order to achieve better voltage stability, principles to add virtual impedance to the inverter's output are described.}, language = {en} } @article{SchaechingerBruecklBeckeretal., author = {Sch{\"a}chinger, J. and Br{\"u}ckl, Oliver and Becker, Mark and Lechner, Raphael}, title = {Results of the Research Project Optibiosy: Biogas plants as stabilizers of the power system?}, series = {BWK ENERGIE}, volume = {74}, journal = {BWK ENERGIE}, number = {11-12}, publisher = {VDI-Verlag}, address = {D{\"u}sseldorf}, issn = {1436-4883}, pages = {34 -- 39}, language = {en} } @article{GamischHuberGadereretal., author = {Gamisch, Bernd and Huber, Lea and Gaderer, Matthias and Dawoud, Belal}, title = {On the Kinetic Mechanisms of the Reduction and Oxidation Reactions of Iron Oxide/Iron Pellets for a Hydrogen Storage Process}, series = {Energies}, volume = {15}, journal = {Energies}, number = {21}, publisher = {MDPI}, doi = {10.3390/en15218322}, abstract = {This work aims at investigating the kinetic mechanisms of the reduction/oxidation (redox) reactions of iron oxide/iron pellets under different operating conditions. The reaction principle is the basis of a thermochemical hydrogen storage system. To simulate the charging phase, a single pellet consisting of iron oxide (90\% Fe2O3, 10\% stabilising cement) is reduced with different hydrogen (H2) concentrations at temperatures between 600 and 800 °C. The discharge phase is initiated by the oxidation of the previously reduced pellet by water vapour (H2O) at different concentrations in the same temperature range. In both reactions, nitrogen (N2) is used as a carrier gas. The redox reactions have been experimentally measured in a thermogravimetric analyser (TGA) at a flow rate of 250 mL/min. An extensive literature review has been conducted on the existing reactions' kinetic mechanisms along with their applicability to describe the obtained results. It turned out that the measured kinetic results can be excellently described with the so-called shrinking core model. Using the geometrical contracting sphere reaction mechanism model, the concentration- and temperature-dependent reduction and oxidation rates can be reproduced with a maximum deviation of less than 5\%. In contrast to the reduction process, the temperature has a smaller effect on the oxidation reaction kinetics, which is attributed to 71\% less activation energy (Ea,Re=56.9 kJ/mol versus Ea,Ox=16.0 kJ/mol). The concentration of the reacting gas showed, however, an opposite trend: namely, to have an almost twofold impact on the oxidation reaction rate constant compared to the reduction rate constant.}, language = {en} } @inproceedings{ArrietaCastroRill, author = {Arrieta Castro, Abel and Rill, Georg}, title = {Kinematic Versus Elasto-Kinematic Model of a Twistbeam Suspension}, series = {Advances in Dynamics of Vehicles on Roads and Tracks II, proceedings of the 27th Symposium of the International Association of Vehicle System Dynamics (IAVSD 2021): August 17-19, 2021, Saint Petersburg, Russia}, booktitle = {Advances in Dynamics of Vehicles on Roads and Tracks II, proceedings of the 27th Symposium of the International Association of Vehicle System Dynamics (IAVSD 2021): August 17-19, 2021, Saint Petersburg, Russia}, editor = {Orlova, Anna and Cole, David}, publisher = {Springer Nature}, doi = {10.1007/978-3-031-07305-2_59}, pages = {505 -- 605}, abstract = {The Twistbeam axle suspension is a cheap and robust layout for rear axles at front wheel driven midsize cars. Appropriate models have to take the elastic deformation of the torsion beam into account. A Finite Element approach requires detailed informations of the material properties and the shape which are usually only available in the final production stage. This paper presents a lumped mass model which can easily be integrated into a multibody vehicle model and can be used in the early stage of development. An approximation by the design kinematics further reduces the complexity of the model and considers only the kinematic properties of the Twistbeam suspension. Simulations using a nonlinear and three-dimensional vehicle model with different maneuvers, such as steady-state cornering, step steer input, and driving straight ahead on random road, demonstrate the performance and, in particular, the difference of the presented Twistbeam suspension models.}, language = {en} } @inproceedings{BuenteRillRuggaberetal., author = {B{\"u}nte, Tilman and Rill, Georg and Ruggaber, Julian and Tobol{\´a}ř, Jakub}, title = {Modelling and Validation of the TMeasy Tyre Model for Extreme Parking Manoeuvres}, series = {Advances in Dynamics of Vehicles on Roads and Tracks II, Proceedings of the 27th Symposium of the International Association of Vehicle System Dynamics (IAVSD 2021): August 17-19, 2021, Saint Petersburg, Russia}, booktitle = {Advances in Dynamics of Vehicles on Roads and Tracks II, Proceedings of the 27th Symposium of the International Association of Vehicle System Dynamics (IAVSD 2021): August 17-19, 2021, Saint Petersburg, Russia}, editor = {Orlova, Anna and Cole, David}, publisher = {Springer}, address = {Cham}, isbn = {978-3-031-07305-2}, doi = {10.1007/978-3-031-07305-2_94}, pages = {1015 -- 1025}, abstract = {The TMeasy is a tyre model suitable for vehicle handling analyses and enables easy parametrisation. Recently, a convenient interface to Modelica was implemented by DLR to support the TMeasy also for vehicle modelling in multi-physical domains. This paper focuses especially on the particular problem of reliable reproduction of the tyre's bore torque which occurs during parking manoeuvres. It outlines the theory behind it, discusses the Modelica interface implementation, and presents the results of parameter identification which were achieved based on real experiments with DLR's research platform ROboMObil.}, language = {en} } @inproceedings{Rill, author = {Rill, Georg}, title = {A Three-Dimensional and Nonlinear Virtual Test Car}, series = {ENOC 2022, book of abstracts, 10th European Nonlinear Dynamics Conference: July 17-22, 2022, Lyon, France}, booktitle = {ENOC 2022, book of abstracts, 10th European Nonlinear Dynamics Conference: July 17-22, 2022, Lyon, France}, address = {Lyon}, pages = {49 -- 58}, abstract = {Virtual testing procedures have become a standard in vehicle dynamics. The increasing complexity of driver assistance sys- tems demand for more and more virtual tests, which are supposed to produce reliable results even in the limit range. As a consequence, simplified vehicle models, like the classical bicycle model or 4-wheel vehicle models, have to be replaced by a fully three-dimensional and nonlinear vehicle model, which also encompasses the details of the suspension systems. This paper presents a passenger car model, where the chassis, the four knuckles, and the four wheels are described by rigid bodies, the suspension system is modeled by the generic design kinematics, and the TMeasy tire model provides the tire forces and torques in all driving situations.}, language = {en} } @article{EmbergerAltmannGebhardetal., author = {Emberger, Peter and Altmann, Robert and Gebhard, J{\"u}rgen and Thuneke, Klaus and Winkler, Markus and T{\"o}pfer, Georg and Rabl, Hans-Peter and Remmele, Edgar}, title = {Combustion characteristics of pure rapeseed oil fuel after injection in a constant volume combustion chamber with a non-road mobile machinery engine solenoid injector}, series = {Fuel}, journal = {Fuel}, number = {320}, publisher = {Elsevier}, doi = {10.1016/j.fuel.2022.123979}, abstract = {Pure rapeseed oil fuel (R100) according to standard DIN 51605 is a greenhouse gas saving option for the mobility sector. With its high energy density close to diesel fuel, R100 is suitable to operate non-road mobile machinery with a high power demand and long operating time, where electric drives reach their limits. Advantages are indicated for its use in environmentally sensitive areas like agriculture since R100 is highly biodegradable and non-toxic. However, R100 is characterised by differing physical and chemical properties compared to diesel. The objective of the research is to investigate the differences in the ignition and combustion behaviour of R100 compared to diesel fuel (DF). For this purpose, a constant volume combustion chamber is used, which is equipped with a modern solenoid injector for engines of non-road mobile machinery. The researched injector shows a different hydraulic behaviour when using R100 compared to DF in that the injected fuel mass is lower with R100 than with DF. In combination with the 14 \% by mass lower calorific value, less energy output is determined with R100. When varying the injection pressure, the impact on the ignition delay and combustion behaviour is much higher for R100 than for DF. Specifically, an increase of the injection pressure supports mixture preparation and thus partially compensates the differing physical properties of R100. The results of ignition delay measurements and net heat release analysis are as follows: At low load conditions with low injection pressure as well as a low combustion chamber temperature and pressure, R100 ignites later and shows a further delayed combustion compared to diesel. The opposite is observed for medium and high load conditions, where R100 ignites faster and without delayed combustion in comparison to DF. Thus, an adjustment of the heat release of R100 at the same level as for DF is possible by modifying the injection strategy. The research shows that for an optimised combustion of R100 the injection settings must be adjusted for every operation point separately. The results indicate how the injection parameters should be adjusted for different load conditions to realise a high-quality engine calibration for R100.}, language = {en} } @inproceedings{LaloSailerMottoketal., author = {Lalo, Erjola and Sailer, Andreas and Mottok, J{\"u}rgen and Siemers, Christian}, title = {Overhead-Aware Schedule Synthesis for Logical Execution Time (LET) in Automotive Systems}, series = {2022 IEEE 35th International System-on-Chip Conference (SOCC): 05-08 September 2022, Belfast, United Kingdom}, booktitle = {2022 IEEE 35th International System-on-Chip Conference (SOCC): 05-08 September 2022, Belfast, United Kingdom}, publisher = {IEEE}, isbn = {978-1-6654-5985-3}, doi = {10.1109/SOCC56010.2022.9908103}, pages = {1 -- 6}, abstract = {The Logical Execution Time (LET) has recently been integrated in multi-core automotive systems to ensure timing and dataflow determinism. Although buffering mechanisms are introduced to incorporate LET semantics, they do not guarantee that tasks are executed within their LET frames. In fact, LET and buffering semantics are violated if scheduling is not designed to execute all tasks within their LET frames and in a specific order. In this paper, we describe a scheduling synthesis technique for Fixed-Priority Scheduling (FPS) to achieve resource-efficient execution of LET systems. The proposed approach considers LET semantics, scheduling overheads, and delays caused by operating system operations and provides the possibility to optimize the schedule with respect to aspects like scheduling overheads. Our performance and feasibility evaluation shows that the proposed algorithm provides results in a reasonable amount of time for models of complex industrial applications. Thus, the integration of the proposed algorithm into an automated process is of high benefit to accelerate the development of vehicle applications.}, language = {en} }