@article{KralHaumerLee, author = {Kral, Christian and Haumer, Anton and Lee, Sang Bin}, title = {A Practical Thermal Model for the Estimation of Permanent Magnet and Stator Winding Temperatures}, series = {IEEE Transactions on Power Electronics}, volume = {29}, journal = {IEEE Transactions on Power Electronics}, number = {1}, publisher = {IEEE}, issn = {1941-0107}, doi = {10.1109/TPEL.2013.2253128}, pages = {455 -- 464}, abstract = {A thermal model for the determination of the temperatures of interior permanent magnets and stator windings is presented in this paper. The innovation of the model relies on one temperature sensor being located in the stator core of the machine. Such sensor is simple to implement in many applications such as traction or EV, where reliability is critical. The estimated stator winding and permanent magnet temperatures are determined by a simplified thermal lumped element network model with only two time constants. It is shown that the proposed thermal model is very robust due to the structure of the model and the measured stator core temperature. The distortion of the temperature estimates caused by the cooling circuit is inherently accounted for such that the model can be used for robust online prediction of temperatures. Experimental results based on a forced water-cooled interior permanent magnet synchronous machine setup are presented to validate the effectiveness of the presented model.}, language = {en} } @inproceedings{HaumerKral, author = {Haumer, Anton and Kral, Christian}, title = {The New EDrives Library: A Modular Tool for Engineering of Electric Drives}, series = {Proceedings of the 10th International Modelica Conference, March 10-12, 2014, Lund, Sweden}, booktitle = {Proceedings of the 10th International Modelica Conference, March 10-12, 2014, Lund, Sweden}, publisher = {Link{\"o}ping University Electronic Press}, isbn = {978-91-7519-380-9}, issn = {1650-3686}, doi = {10.3384/ecp14096155}, pages = {155 -- 163}, abstract = {Simulation is an indispensable tool for the engineering of systems containing electric drives. Depending on the design phase and the engineering task different levels of modeling details are required: proof of concept; investigation of energy and power consumption; design of control; etc. The new EDrives library provides three levels of abstraction for inverters: quasi static (neglecting electrical transients); averaging (neglecting switching effects) and switching - for serving different demands. The inverters can feed the machine models of the Modelica Standard Library: Modelica.Magnetic.FundamentalWave and the new Modelica.Magnetic.QuasiStatic.FundamentalWave. The EDrives library copes with arbitrary phase numbers and can be easily extended to develop new control algorithms. In this publication the structure of the library and the implemented control principles are presented. Furthermore; examples comparing the three different levels of abstraction are included.}, language = {en} } @inproceedings{KralHaumerWoehrnschimmel, author = {Kral, Christian and Haumer, Anton and W{\"o}hrnschimmel, Reinhard}, title = {Extension of the FundamentalWave Library towards Multi Phase Electric Machine Models}, series = {Proceedings of the 10th International Modelica Conference, March 10-12, 2014, Lund, Sweden}, booktitle = {Proceedings of the 10th International Modelica Conference, March 10-12, 2014, Lund, Sweden}, publisher = {Link{\"o}ping University Electronic Press}, isbn = {978-91-7519-380-9}, issn = {1650-3686}, doi = {10.3384/ecp14096135}, pages = {135 -- 143}, abstract = {Abstract Electric machine theory and electric machine simulations models are often limited to three phases. Up to the Modelica Standard Libray (MSL) version 3.2 the provided machine models were limited to three phases. Particularly for large industrial drives and for redundancy reasons in electric vehicles and aircrafts multi phase electric machines are demanded. In the MSL 3.2.1 an extension of the existing FundamentalWave library has been performed to cope with phase numbers greater than or equal to three. The developed machine models are fully incorporating the multi phase electric; magnetic; rotational and thermal domain. In this publication the theoretical background of the machines models; Modelica implementation details; the parametrization of the models and simulation examples are presented.}, language = {en} } @inproceedings{KasparRablMayer, author = {Kaspar, Marcel and Rabl, Hans-Peter and Mayer, Wolfgang}, title = {Differenzierte Kohlenwasserstoffanalytik im Dieselabgas bei verschiedenen Motorbetriebszustaenden : Detailed hydrocarbon analysis of diesel exhaust gas at different engine operating conditions}, series = {12. FAD-Konferenz „Herausforderung - Agbasnachbehandlung f{\"u}r Dieselmotoren", 12, 2014, Dresden}, booktitle = {12. FAD-Konferenz „Herausforderung - Agbasnachbehandlung f{\"u}r Dieselmotoren", 12, 2014, Dresden}, publisher = {F{\"o}rderkreis Abgasnachbehandlungstechnologien f{\"u}r Verbrennungskraftmaschinen (FAD) e.V.}, address = {Dresden}, pages = {1 -- 35}, abstract = {Beitrag und Praesentationsmaterial eines Vortrags ueber differenzierende Kohlenwasserstoffanalytik im Dieselabgas bei verschiedenen Motorbetriebszustaenden. Mit einem neu entwickelten, hochgenauen HC-Sensor werden unverbrannte HC im Abgas untersucht. Die differenzierende Untersuchung erfolgt an einem Massenspektrometer, das mit chemischer Ionisation arbeitet. Die Molekuele Ethin, Ethen und Propen wurden gezielt betrachtet. Es zeigt sich, dass bei kalten Betriebsbedingungen diese drei Komponenten etwa die Haelfte der gesamten HC Konzentration ergeben. Ein weiterer Punkt ist die Regeneration des Dieselpartikelfilters.}, language = {de} } @book{RillSchaeffer, author = {Rill, Georg and Schaeffer, Thomas}, title = {Grundlagen und Methodik der Mehrk{\"o}rpersimulation : Vertieft in Matlab-Beispielen, {\"U}bungen und Anwendungen}, publisher = {Springer}, address = {Berlin}, doi = {10.1007/978-3-658-06084-8}, pages = {215}, abstract = {Dieses Lehrbuch vermittelt nicht nur Grundlagen, sondern stellt auch die Methoden der Mehrk{\"o}rpersimulation anschaulich dar und erl{\"a}utert an einfachen Beispielen die Vor- und Nachteile bei der praktischen Anwendung. In den Text integrierte Matlab-Skripte und -Funktionen verdeutlichen die einzelnen Methoden und erm{\"o}glichen es, Aufwand und Problematik bei der Umsetzung der Theorie innerhalb von Simulationsprogrammen einzusch{\"a}tzen. Die Modellbildung, die mathematische Beschreibung und die numerische Simulation von Systemen starrer K{\"o}rper bilden dabei die Schwerpunkte. Konkret behandelte Beispiele sind die Eigendynamik eines Traktors mit gefederter Vorderachse, das Rotorblatt eines Hubschraubers sowie die Vorderachse eines Pkws. Die entsprechenden Matlab-Skripte und L{\"o}sungen zu den {\"U}bungsaufgaben k{\"o}nnen auf der Springer-Homepage beim Buch heruntergeladen werden. Der Inhalt Dynamik des starren K{\"o}rpers - Bewegungsgleichungen - Starre K{\"o}rper mit elastischen und kinematischen Verbindungselementen - Integrationsverfahren - Rekursiver Algorithmus - Differential-Algebraische Gleichungen - Analyse von Mehrk{\"o}rpersystemen - Anwendungs- und {\"U}bungsbeispiele aus der Technik Die Zielgruppen Studenten des Maschinenbaus, der Elektrotechnik und Mechatronik sowie der Biomechanik an Hochschulen und Universit{\"a}ten Ingenieure in der Praxis, die sich mit Fragestellungen der Mehrk{\"o}rpersimulation (MKS) befassen Entwickler aus der Kfz-Technik sowie Fachleute aus F+E Die Autoren Dr.-Ing. Georg Rill ist Professor mit den Lehrgebieten Technische Mechanik, Ingenieurinformatik, Fahrdynamik, Mehrk{\"o}rperdynamik sowie Laborleiter Fahrdynamik. Dr.-Ing. Thomas Schaeffer ist Professor mit den Lehrgebieten Konstruktion, CAD, Maschinenelemente und Getriebetechnik, Mehrk{\"o}rpersysteme und Bewegungstechnik sowie Laborleiter Mehrk{\"o}rpersimulation, beide an der Ostbayerischen Technischen Hochschule (OTH) Regensburg.}, language = {de} } @misc{Urban, type = {Master Thesis}, author = {Urban, Johannes}, title = {Photoelektrisches Direktladen von Elektrofahrzeugen im Inselbetrieb}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:898-opus4-20285}, school = {Ostbayerische Technische Hochschule Regensburg}, pages = {118}, abstract = {Die Arbeit befasst sich mit der Ladung von Elektrofahrzeugen durch Solarenergie in einem Inselsystem. Diese Art der Ladung entlastet die Netze und hat einen sehr hohen Leistungswirkungsgrad. Es wurde ein Prototyp einer Direkt-ladestation gebaut, welche verschiedene Elektrofahrzeuge mit einem neuartigen Verfahren aufladen kann. Sie enth{\"a}lt einen optionalen Pufferakkumulator und einen Vollbr{\"u}cken-Gegentaktwandler f{\"u}r die Ladung bei schlechter Solarleistung. Ein Teil der Arbeit behandelt ausf{\"u}hrlich die Auslegung, die Komponenten und bisher undokumentiertes Verhalten von Gegentaktwandlern. Des Weiteren wird das Prinzip der Solardirekt-ladung und deren Umsetzung sowie die Umsetzung des Gesamtsystems beschrieben. Es folgt ein Kapitel zur Wirtschaftlichkeit der Solardirektladung mit Handlungsempfehlungen. Insgesamt l{\"a}sst sich schließen, dass Solardirektladung bei nutzungsorientierter Auslegung der Anlage und langer Laufzeit wirtschaftlich ist. This work addresses the charging of electric vehicles with solar power in an off-grid system. Charging this way reduces the stress on the grid and has a very high power efficiency. A prototype of a direct charging station was built which is able to charge several different electric vehicles in a novel way. It includes an optional buffer battery and a full bridge converter for being able to charge electric vehicles at times o flow solar power. One chapter explains in detail the design, the components and so far undocumented properties of full and half bridge converters. The principle and the implementation of direct solar charging and the implementation of the whole system is described. The last chapter covers the cost effectiveness of solar chargin gas well as recommendations. All in all it can be stated that solar direct charging is ecomomically advantageous if it is projected according to the user's demand.}, subject = {Fotovoltaik}, language = {de} } @inproceedings{VoellingNonnSchneider, author = {V{\"o}lling, Alexander and Nonn, Aida and Schneider, Ingo}, title = {Anwendung des Koh{\"a}sivzonenmodells zur Abbildung von duktilem dynamischen Rissfortschritt in Gasfernleitungen}, series = {45. Tagung des AK Bruch, Berlin, Germany}, booktitle = {45. Tagung des AK Bruch, Berlin, Germany}, pages = {253 -- 262}, subject = {Ferngasleitung}, language = {de} } @inproceedings{NonnKalwa, author = {Nonn, Aida and Kalwa, Christoph}, title = {Analysis of dynamic ductile fracture propagation in pipeline steels}, series = {6th Pipeline Technology Conference (2013), Ostend, Belgium}, booktitle = {6th Pipeline Technology Conference (2013), Ostend, Belgium}, doi = {10.13140/2.1.4370.3046}, abstract = {Analysis of dynamic ductile fracture propagation in pipeline steels: a damage-T IS A WELL-ESTABLISHED fact that the successful application of new generation of high-strength steel grades for long-distance gas transmission depends strongly on full understanding and appropriate characterization of fracture resistance. A damage mechanics approach has found to be a very promising tool in supporting the experimental characterization of ductile fracture propagation. The major advantage of this approach lies in the consideration of the influence of local stress and strain variables on the damage evolution and thus its capability to describe the fracture resistance of the pipelines with different stress triaxiality level by using the same set of parameters. However, the wider application of this approach has been limited due to the issues such as reliable determination of input parameters and required material properties, mesh size dependence, etc.. The objective of this paper is to characterize dynamic ductile fracture resistance of X65 and X80 pipeline materials and to demonstrate the potential of damage mechanics approach for the simulation of dynamic fracture propagation by using two damage models: (1) Cohesive Zone (CZ) model and (2) Gurson-Tvergaard-Needleman (GTN) model. In the first step, results from quasi-static and dynamic tensile tests are used to describe plasticity in terms of flow curves. The calibration of input parameters for both models is performed by using the load-deformation curves from quasi-static tests on non-standard drop-weight tear (DWT) specimens with pre-fatigued crack. b. In the next step, estimated damage model parameters are verified by means of the dynamic tests on the pressed and Chevron notch DWT specimens. Different amounts of crack growth are established by varying the drop height. The experimental fracture resistance is quantified in terms of J-integral at specific crack length. The numerical results are evaluated with respect to global load-deformation and fracture resistance behavior. Furthermore, damage simulations are applied for quantification of local stress conditions in order to identify the major factors controlling the crack propagation. The results reported here serve as a basis for better understanding of fracture performance in dependences of geometry and material properties.}, language = {en} } @inproceedings{NonnKalwa, author = {Nonn, Aida and Kalwa, Christoph}, title = {Application of probabilistic fracture mechanics for safety assessment of longitudinally welded linepipes}, series = {6th Pipeline Technology Conference (2013), Ostend, Belgium}, booktitle = {6th Pipeline Technology Conference (2013), Ostend, Belgium}, language = {en} } @inproceedings{NonnKalwa, author = {Nonn, Aida and Kalwa, Christoph}, title = {Application of damage mechanics approach for crack propagation in pipeline}, series = {19th Biennial Joint Technical Meeting (JTM) on Pipeline Research, April 29 - May 3, 2013, Sydney, Australia}, booktitle = {19th Biennial Joint Technical Meeting (JTM) on Pipeline Research, April 29 - May 3, 2013, Sydney, Australia}, language = {en} } @inproceedings{NonnWesselSchmidt, author = {Nonn, Aida and Wessel, Waldemar and Schmidt, Tanja}, title = {Application of finite element analysis for assessment of fracture behavior of modern high toughness seamless pipeline steels}, series = {23rd International Society of Offshore and Polar Engineering 2013 (ISOPE 2013), Anchorage, USA}, booktitle = {23rd International Society of Offshore and Polar Engineering 2013 (ISOPE 2013), Anchorage, USA}, doi = {10.13140/2.1.4239.2322}, abstract = {Fracture behavior of seamless pipeline material X65Q acc. to API 5L has been studied both experimentally and numerically at different loading conditions (quasi-static vs. dynamic) and temperatures. The recent findings have shown difficulties in applying well established methods for determination of transition behavior or prediction of ductile crack arrest for the new generation of high-toughness steels. The irregular fracture performance (e.g. so-called "abnormal inverse fracture" appearance, significant scattering in ductile-to-brittle-transition-temperature region, etc.) suggests that the influence of pipe dimensions, loading parameters, crack initiation resistance as well as testing procedure on the fracture behavior has been neither understood nor properly described. This work aims to shed light on these questions regarding the applicability of conventional methods and to better illuminate most relevant parameters affecting fracture behavior of high toughness steels. To achieve this goal, experimental data basis for analysis of fracture behavior in transition and upper shelf regime has been established by conducting quasi-static fracture mechanics tests and dynamic tests on Battelle Drop Weight Tear (BDWT or DWT) specimens at different temperatures. The evaluation of obtained test results in upper shelf has been additionally complemented by numerical simulation of damage behavior. The results highlight the influence of stress conditions on fracture behavior with reference to pipe dimensions and loading conditions and, subsequently, may be used as a basis for revision of existing design methods.}, subject = {Rissfortschritt}, language = {en} } @inproceedings{ZengerKennerVolbertetal., author = {Zenger, Gerhard and Kenner, Susanne and Volbert, Klaus and Waas, Thomas and Kucera, Markus}, title = {Acquiring energy data from a medium-voltage grid for future smart grid solutions: A practical smart grid application example realized by use of cellular communication networks of the 2nd and 3rd generation}, series = {Proceedings of the 11th Workshop on Intelligent Solutions in Embedded Systems (WISES), 10-11 Sept. 2013, Pilsen, Czech Republic}, booktitle = {Proceedings of the 11th Workshop on Intelligent Solutions in Embedded Systems (WISES), 10-11 Sept. 2013, Pilsen, Czech Republic}, publisher = {IEEE}, isbn = {978-3-00-042899-9}, pages = {1 -- 8}, abstract = {In this paper we present a practical example of the use of Cellular Communication standards like GPRS and UMTS in a Smart Grid Application. For a more detailed view we demonstrate a possible implementation of Cellular Communication Technologies in a data acquisition application for the collection of energy indicators in a medium-voltage grid. Furthermore, we show a technical overview of relevant and common mobile communication standards available in Germany. The included theoretical examples, Smart Grid scenarios, presented data and results are based on a research project for intelligent power regulation in medium-voltage grids performed in Regensburg (Germany). It is a joint project' of the University of Applied Sciences Regensburg together with a local energy provider and a manufacturer for distribution network systems.}, language = {en} } @article{FreniFrazzicaDawoudetal., author = {Freni, Angelo and Frazzica, Andrea and Dawoud, Belal and Chmielewski, Stefanie and Calabrese, Luigi and Bonaccorsi, Lucio Maria}, title = {Adsorbent coatings for heat pumping applications: Verification of hydrothermal and mechanical stabilities}, series = {Applied Thermal Engineering}, volume = {50}, journal = {Applied Thermal Engineering}, number = {2}, publisher = {Elsevier}, doi = {10.1016/j.applthermaleng.2011.07.010}, pages = {1658 -- 1663}, abstract = {This paper presents novel experimental methods for verification of both hydrothermal and mechanical stabilities of adsorbent coatings. Experiments have been carried out on zeolite-based coatings over aluminum substrates, prepared by a dip-coating technique developed at CNR-ITAE. Hydrothermal aging of several adsorbent coatings is ongoing. Adsorption and structural stability of some samples under test was successfully verified after 35000 aging cycles by isobars measurement and XRD analysis. Mechanical properties of coatings have been evaluated by applying different typologies of static and dynamic mechanical stresses. Results obtained have been compared with those achieved by subjecting adsorbent coatings prepared by Mitsubishi Plastic Incorporation (MPI) to the same characterization protocol. The comparison between the two types of coating returned that MPI coatings posses similar thermal stability and better mechanical strength than CNR-ITAE coatings.}, language = {en} } @article{Dawoud, author = {Dawoud, Belal}, title = {Water vapor adsorption kinetics on small and full scale zeolite coated adsorbers; A comparison}, series = {Applied thermal engineering}, volume = {50}, journal = {Applied thermal engineering}, number = {2}, publisher = {Elsevier}, doi = {10.1016/j.applthermaleng.2011.07.013}, pages = {1645 -- 1651}, abstract = {A possibility to enhance both heat and mass transfer characteristics of an adsorber heat exchanger is to apply the adsorbent directly to its surface in form of a consolidated layer. As the majority of the available publications on the effect of both coating technology and adsorbent layer thickness on the adsorption kinetics deals with small scale adsorbent samples, the results obtained can only represent the best case design of an adsorber heat exchanger. This article presents, therefore, a comparison between the adsorption kinetics of water vapour on small as well as two different full scale coated adsorber heat exchanger types with AQSOA-Z02 layers of Mitsubishi Plastics Incorporation under quasi isobaric conditions of adsorption heat pumps. The small scale coated samples have a zeolite dry mass of 200 mg and layer thicknesses of 200, 300 and 500 μm while the full scale adsorbers have a coated zeolite mass between 1.5 and 2.5 kg and layer thicknesses of 150, 200, 300, 400 and 500 μm. In the investigated adsorption heat pump module, up to 52.7 and 57.3\% of the equilibrium differential water loading measured with the small scale coated substrates have been obtained after an adsorption-evaporation times of 300 and 600 s, respectively.}, language = {en} } @article{KuepperArtmannPischingeretal., author = {K{\"u}pper, Carsten and Artmann, Christina and Pischinger, Stefan and Rabl, Hans-Peter}, title = {Schmier{\"o}lverd{\"u}nnung von direkteinspritzenden Ottomotoren unter Kaltstartrandbedingungen}, series = {MTZ - Motortechnische Zeitschrift}, volume = {74}, journal = {MTZ - Motortechnische Zeitschrift}, number = {9}, publisher = {Springer Vieweg}, address = {Wiesbaden}, doi = {10.1007/s35146-013-0208-1}, pages = {710 -- 715}, language = {de} } @article{KuepperArtmannPischingeretal., author = {K{\"u}pper, Carsten and Artmann, Christina and Pischinger, Stefan and Rabl, Hans-Peter}, title = {Lube-Oil Dilution of Gasoline Direct-Injection Engines with Ethanol Fuels}, series = {MTZ worldwide}, volume = {74}, journal = {MTZ worldwide}, number = {9}, publisher = {Springer}, address = {Berlin}, doi = {10.1007/s38313-013-0090-8}, pages = {64 -- 69}, language = {en} } @inproceedings{BruecklKrpalRiepl, author = {Br{\"u}ckl, Oliver and Krpal, Ondrej and Riepl, Markus}, title = {Influence of wind and solar energy on the frequency of switching operations of On-Load Tap-Changers (OLTC)}, series = {Proceedings of the 13th International Scientific Conference Electric Power Engineering 2012, EPE 2012; Vol. 2}, booktitle = {Proceedings of the 13th International Scientific Conference Electric Power Engineering 2012, EPE 2012; Vol. 2}, publisher = {EPE}, address = {Brno, Czech Republic}, organization = {Brno University of Technology / Faculty of Electrical Engineering and Communication Department of Electrical Power Engineering and Centre for Research and Utilization of Renewable Energy}, pages = {719 -- 722}, language = {en} } @inproceedings{NonnKalwa, author = {Nonn, Aida and Kalwa, Christoph}, title = {Simulation of ductile crack propagation in high-strength pipeline steel using damage models}, series = {9th International Pipeline Conference 2012 (IPC 2012), Calgary, Canada}, booktitle = {9th International Pipeline Conference 2012 (IPC 2012), Calgary, Canada}, doi = {10.1115/IPC2012-90653}, pages = {7}, abstract = {The performance of engineering design of high-strength steel pipelines has revealed the necessity to revise current design procedures. Therefore, an improved and detailed comprehension of fracture mechanisms and development of failure prediction tools are required in order to derive new design criteria. In last decades the most successful failure prediction tools for steel structures subjected to various type of loading can be encountered in the field of damage mechanics. This paper aims to describe ductile fracture behavior of high-strength steel pipelines by applying three different damage models, Gurson-Tvergaard-Needelman (GTN), Fracture Locus Curve (FLC) and Cohesive Zone (CZ). These models are evaluated regarding their capability to estimate ductile crack propagation in laboratory specimens and linepipe components without adjusting the calibrated parameters. It can be shown that appropriate parameter sets can be identified to reproduce load-deformation and fracture resistance curves accurately. The strain rate effect on the fracture behavior is examined by dynamic tests on the BDWT specimens. Finally, the shortcomings of the applied models are pointed out with the reference to possible extensions and modifications.}, language = {en} } @inproceedings{MiedlBraun, author = {Miedl, Christian and Braun, J{\"u}rgen}, title = {Powertrain and electric system design of a 800-volt all-electric car}, series = {European Conference on Nanoelectronics and Embedded Systems for Electric Mobility, eMotion in Smart Cities, 24.-28. September, 2012, Bologna, Italy}, booktitle = {European Conference on Nanoelectronics and Embedded Systems for Electric Mobility, eMotion in Smart Cities, 24.-28. September, 2012, Bologna, Italy}, language = {en} } @article{OstermeierMottokKnorretal., author = {Ostermeier, Daniel and Mottok, J{\"u}rgen and Knorr, Christine and Huber, Michael}, title = {Competence Atlas for Save and Green Road Vehicles in the Electro Mobility Cluster Regensburg}, series = {Applied Research Conference 2012 (ARC 2012) 25./26. June 2012, Nuremberg}, journal = {Applied Research Conference 2012 (ARC 2012) 25./26. June 2012, Nuremberg}, editor = {Mottok, J{\"u}rgen and Ziemann, Olaf}, pages = {86 -- 92}, language = {en} }