@inproceedings{NonnErdelenPepplerWesseletal., author = {Nonn, Aida and Erdelen-Peppler, Marion and Wessel, Waldemar and Harksen, Silke and Mahn, Denise}, title = {How to assure fracture-propagation control for seamless gas pipelines?}, series = {Proceedings of the 2014 10th International Pipeline Conference (IPC2014), Volume 3: Operations, Monitoring, and Maintenance, Materials and Joining, September 29-October 3, 2014, Calgary, Canada}, booktitle = {Proceedings of the 2014 10th International Pipeline Conference (IPC2014), Volume 3: Operations, Monitoring, and Maintenance, Materials and Joining, September 29-October 3, 2014, Calgary, Canada}, doi = {10.1115/IPC2014-33169}, abstract = {Fracture propagation control in gas transmission gas pipelines belongs to the major design requirements for safe operation at high internal pressures. However, the current tests such as Drop-Weight-Tear Test (DWTT) and full-scale West-Jefferson (WJ) test reach the limits of their applicability with respect to transition temperature evaluation for seamless quenched and tempered small diameter pipes reflecting nowadays alloying concepts related to mechanical properties. Hereby, different geometry and material effects are evident which might lead to misinterpretation and unreliability of testing results. This paper aims to discuss open issues addressed in the literature and in own experimental findings with respect to reliability and transferability of testing methods, fracture parameters and their representativeness of seamless quenched and tempered pipeline behavior. By applying damage mechanics approach, it is possible to quantify the prevailing stress state and thus to understand the mechanisms controlling specific fracture appearance (ductile or brittle). Furthermore, studies were performed with objective to quantify the effect of different parameters (geometry, material and loading) on the fracture performance of the pipeline. The results from these investigations will serve as a basis for a safe pipeline design against propagating fracture.}, language = {en} } @inproceedings{KarbasianGrossWeegeNonnetal., author = {Karbasian, H. and Groß-Weege, J. and Nonn, Aida and Zimmermann, S. and Kalwa, Christoph}, title = {Assessment of collapse resistance of UOE pipes - comparison of full-scale and ring collapse tests}, series = {Proceedings of the 10th International Pipeline Conference 2014 (IPC 2014), September 29 - October 3, 2014, Calgary, Alberta, Canada}, booktitle = {Proceedings of the 10th International Pipeline Conference 2014 (IPC 2014), September 29 - October 3, 2014, Calgary, Alberta, Canada}, language = {en} } @inproceedings{SchneiderNonnVoellingetal., author = {Schneider, Ingo and Nonn, Aida and V{\"o}lling, Alexander and Mondry, A. and Kalwa, Christoph}, title = {A damage mechanics based evaluation of dynamic fracture resistance in gas pipelines}, series = {Procedia Materials Science, Volume 3}, volume = {3}, booktitle = {Procedia Materials Science, Volume 3}, doi = {10.1016/j.mspro.2014.06.315}, pages = {1956 -- 1964}, abstract = {Investigation of running ductile fracture in gas transmission pipelines and the derivation of reliable crack arrest prediction methods belong to major topics in pipeline research. The yet available crack arrest criterion, known as the Battelle Two-Curve Method (BTCM), leads to reliable predictions up to grade X70 line pipe steels for which it has been validated. This includes specific limits in terms of mechanical properties, pressure and geometry. The application of this criterion to modern pipeline steels, i.e. especially grades X80 and beyond in combination with larger diameters and high pressure, has led to mispredictions of the BTCM. Hence, in order to ensure safe design of pipelines, new methods are required based on in depth knowledge and appropriate characterization of material resistance. This paper presents a procedure for the assessment of dynamic ductile fracture resistance based on combined experimental and numerical investigations. The procedure involves quasi-static and dynamic drop- weight tear testing (DWTT) on modified specimens with pre-fatigued crack for grades X65, X80 and X100 materials, and the application of cohesive zone (CZ) and Gurson-Tveergard-Needleman (GTN) models to describe ductile material damage. The damage model parameters are calibrated on basis of DWTT results and subsequently used to simulate dynamic crack propagation in a pipeline. The influence of material properties (strain hardening, toughness), pipe geometry, usage factor and decompression behaviour on ductile fracture propagation behaviour is studied and evaluated. The results will contribute to an enhanced understanding of major parameters controlling ductile fracture propagation and will help to establish a reliable procedure for safe design of new high-capacity pipelines with regard to crack arrest.}, language = {en} } @article{EbnerElsner, author = {Ebner, Lena and Elsner, Michael}, title = {Thermische Energiespeicher: W{\"a}rmespeicherung in Kugelsch{\"u}ttungen. Numerische Simulation der Stromungs-, Warmetransport- und Entstaubungsvorg{\"a}nge}, series = {BWK. Das Energie-Fachmagazin}, volume = {66}, journal = {BWK. Das Energie-Fachmagazin}, number = {9}, publisher = {VDI-Verlag}, pages = {40 -- 43}, abstract = {Festbettspeicher bieten die M{\"o}glichkeit, thermische Energie auf einem hohen Temperaturniveau zu speichern. Die oft kugelf{\"o}rmigen Sch{\"u}ttg{\"u}ter bestehen aus Materialien hoher Dichte und W{\"a}rmekapazit{\"a}t. Neben der W{\"a}rmespeicherung k{\"o}nnen mithilfe dieser Sch{\"u}ttungen partikelbeladene Abgase entstaubt werden. Die Str{\"o}mungs-, W{\"a}rmetransport- und Entstaubungsvorg{\"a}nge bei der Speicherung von W{\"a}rme in einem Sch{\"u}ttschichtw{\"a}rme{\"u}bertrager werden in Zusammenarbeit mit Fraunhofer Umsicht, Institutsteil Sulzbach-Rosenberg, untersucht. Einen entscheidenden Aspekt der Arbeiten stellt die numerische Simulation der im W{\"a}rme{\"u}bertrager ablaufenden Vorg{\"a}nge dar. Die transiente Simulation von Sch{\"u}ttschichtw{\"a}rme{\"u}bertragern ist nur mit Vereinfachungen m{\"o}glich, da aufgrund der komplexen Geometrie und der daraus folgenden feinen Vernetzung eine enorme Rechenleistung ben{\"o}tigt wird. Bei den in diesem Beitrag vorgestellten Ergebnissen werden die physikalischen Vorgange in einem Ausschnitt der Sch{\"u}ttschicht simuliert, in dem die Kugelgeometrie detailliert modelliert ist. Die Ergebnisse der numerischen Simulation werden durch analytische Berechnungen aus der Literatur best{\"a}tigt. Eine Reihe von Parametervariationen zeigen die Einfl{\"u}sse verschiedener Gr{\"o}ßen beispielsweise auf den Druckverlust sowie den Unterschied zwischen radialer und axialer Durchstr{\"o}mung einer Sch{\"u}ttschicht. Die Entstaubung partikelbeladener Gase innerhalb einer Sch{\"u}ttschicht wird zun{\"a}chst anhand einer Einzelkugel untersucht; die Erweiterung auf die Entstaubung in einer Kugelpackung ist vorgesehen. Die Ergebnisse der numerischen Simulationen sollen mit den an einem Versuchsstand experimentell bestimmten Daten verglichen werden.}, language = {de} } @inproceedings{KasparRabl, author = {Kaspar, Marcel and Rabl, Hans-Peter}, title = {Differenzierte Kohlenwasserstoffanalytik im Dieselabgas bei verschiedenen Motorbetriebszust{\"a}nden}, 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.}, pages = {45 -- 59}, abstract = {Die f{\"u}r Dieselfahrzeuge gesetzlich vorgeschriebenen Grenzwerte bez{\"u}glich der Schadstoffkomponenten Kohlenwasserstoffe und Kohlenmonoxid k{\"o}nnen nur durch den Einsatz eines Diesel-Oxidationskatalysators erf{\"u}llt werden. Um erh{\"o}hte Emissionen infolge eines gesch{\"a}digten Katalysators zu vermeiden, gilt es, dieses abgasrelevante Bauteil auch w{\"a}hrend des Betriebes zu {\"u}berwachen. Die zuk{\"u}nftigen gesetzlichen Anforderungen an die {\"U}berwachung erfordern ein Verfahren das eine zuverl{\"a}ssige und hochgenaue Diagnose zul{\"a}sst. Deshalb entwickelt eine Forschungsgemeinschaft aus Industrieunternehmen und Hochschulen einen neuartigen Kohlenwasserstoffsensor zur hochgenauen Analyse von unverbrannten Kohlenwasserstoffen im Abgasstrang. Hierf{\"u}r ist die Kohlenwasserstoffzusammensetzung des Dieselabgases bei verschiedenen Motorbetriebszust{\"a}nden zu ermitteln. Zur differenzierten Untersuchung der Kohlenwasserstoffkomponenten wurde in der Arbeit ein Massenspektrometer eingesetzt, das mit chemischer Ionisation arbeitet. Anhand eines Abgasscreenings konnte eine Reihe von Kohlenwasserstoffen (Alkane, Alkene, Alkine, Alkadiene und aromatische Kohlenwasserstoffe) identifiziert werden, die typisch f{\"u}r das Dieselabgas stehen. Die Molek{\"u}le Ethin, Ethen und Propen wurden gezielt betrachtet. Die Ergebnisse zeigen, dass bei kalten Betriebsbedingungen diese drei Komponenten etwa die H{\"a}lfte der Gesamtkohlenwasserstoffkonzentration ergeben. Ein weiterer Punkt der Untersuchungen war die Diesel-Partikelfilter-Regeneration. Wie erwartet, lassen sich Kohlenwasserstoffmolek{\"u}le mit h{\"o}heren Massen feststellen, die auf unverbrannten Dieselkraftstoff zur{\"u}ckzuf{\"u}hren sind. Anhand der Ergebnisse zeigte sich.dass sich das mit chemischer Ionisation arbeitende Massenspektrometer hervorragend f{\"u}r ein Abgasscreening eignet. Zahlreiche Kohlenwasserstoffe konnten identifiziert werden, die repr{\"a}sentativ f{\"u}r das Dieselabgas stehen. Es sollten Molek{\"u}le bei verschiedenen Motorbetriebsbedingungen untersucht werden, die einen m{\"o}glichst großen Anteil an der Gesamtkohlenwasserstoffkonzentration besitzen. Die Auswahl fiel aufgrund der gemessenen Massenspektren, vor und nach dem Diesel-Oxidationskatalysator, auf die Komponenten Ethin, Ethen und Propen. Zudem kann bei diesen Molek{\"u}len eine Masseninterferenz mit anderen Abgaskomponenten ausgeschlossen werden. Im unteren Teillastbereich und kaltem Motor machen diese Kohlenwasserstoffe bis zu 50\%, gemittelt {\"u}ber alle Messstellen vor, im und nach dem Diesel-Oxidationskatalysator, der Gesamtkohlenwasserstoffkonzentration aus. Bei betriebswarmem Motor reduziert sich ihr Anteil auf ein Drittel Die h{\"o}chste Konzentration unter den drei Komponenten besitzt dabei Propen. Mit steigendem Drehmoment nimmt der Anteil dieser drei Komponenten fortlaufend ab,was daf{\"u}r spricht, dass Molek{\"u}le mit h{\"o}heren Massen einen h{\"o}heren Anteil einnehmen. Die Kohlenwasserstoff-Emissionen bewegen sich bei diesen Motorbetriebspunkten mit betriebswarmem Katalysator jedoch bereits bei sehr niedrigen Werten. W{\"a}hrend der untersuchten Diesel-Partikelfilter-Regeneration mit sp{\"a}ten Nacheinspritzungen zur Abgastemperaturerh{\"o}hung lassen sich Molek{\"u}le mit h{\"o}heren Massen nachweisen. Diese sind typisch f{\"u}r die Reinkomponente Dieselkraftstoff. Der Anteil von Ethin, Ethen und Propen an der THC-Konzentration betr{\"a}gt dann ca. 40\%.}, language = {de} } @inproceedings{MilaevRuiderSchlegl, author = {Milaev, Johannes and Ruider, Martin and Schlegl, Thomas}, title = {Entwicklung eines Experimentalsystems zur Validierung adaptiver Regelungen mit einem OEM-Steuerger{\"a}t}, series = {Tagungsband AALE 2014 : das Forum f{\"u}r Fachleute der Automatisierungstechnik aus Hochschulen und Wirtschaft ; 11. Fachkonferenz, Regensburg}, booktitle = {Tagungsband AALE 2014 : das Forum f{\"u}r Fachleute der Automatisierungstechnik aus Hochschulen und Wirtschaft ; 11. Fachkonferenz, Regensburg}, publisher = {Deutscher Industrieverlag}, address = {M{\"u}nchen}, isbn = {978-3-8356-7142-3}, pages = {241 -- 250}, abstract = {Im Rahmen des Kooperationsprojektes "ACES" (Integrated Adaption of Linear Controllers for Embedded Systems) ist ein Pr{\"u}fstand zur Validierung adaptiver Regelungen entwickelt und aufgebaut worden, der das dynamische Verhalten eines Kfz-Antriebstrangs aufweist. Ziel ist es, verschiedene Adaptionsverfahren auf ihre Einsetzbarkeit in OEM-Steuerger{\"a}ten, die im Automotive-Bereich auf breiter Basis verwendet werden, kosteng{\"u}nstig testen zu k{\"o}nnen. Das Problem der aktiven Schwingungsd{\"a}mpfung in Kfz-Antriebsstr{\"a}ngen mit unbekannten und ver{\"a}nderlichen mechanischen Parametern stellt eine Pilotanwendung dar. Ein leicht anpassbarer mechanischer Pr{\"u}fstand dient hierbei als vereinfachtes Modell eines Antriebstrangs. Dieser ist Bestandteil eitles Experimentalsystems mit einer informationstechnischen Architektur, die einen Betrieb engebetteter Regelungssysteme auf verschiedenen Plattformen gestattet. Das flexible mechanische und informationstechnische Design des Experimentalsystems gestattet die Variation von Parametern der zu regelnden Applikation durch leicht austauschbare mechanische Komponenten und gezielte Einbringung von St{\"o}rgr{\"o}ßen. Zudem kann die Berechnung der Regelungsarchitektur auf einem Industrie-PC oder einem Steuerger{\"a}t erfolgen. Weitere Vorteile des entwickelten Experimentalsystems sind die Ber{\"u}cksichtigung von Effekten, die aus dem Verhalten realer Sensoren und der CAN-basierten Signal{\"u}bertragung entstehen. Insbesondere der Einfluss von Wortbreite und Latenz {\"u}bertragener Signale auf die Adaption von Regelungen kann mit Hilfe des vorgestellten Experimentalsystems eingehend untersucht werden.}, language = {de} } @inproceedings{SchmidtFuchsFuchs, author = {Schmidt, Hans-Peter and Fuchs, Andreas and Fuchs, Stefan}, title = {Simultaneous contact less charging of multiple electric vehicles: Contact less power and data transfer for multiple distributed loads}, series = {2014 4th International Electric Drives Production Conference ( 30 Sept.-1 Oct. 2014, Nuremberg, Germany}, booktitle = {2014 4th International Electric Drives Production Conference ( 30 Sept.-1 Oct. 2014, Nuremberg, Germany}, publisher = {IEEE}, doi = {10.1109/EDPC.2014.6984435}, pages = {1 -- 3}, abstract = {A design of a 3-phase inductive power and data transfer for multiple stationary loads is proposed. It focuses on stable load voltages while minimizing electromagnetic interference. Loads are contactless charging units of electric vehicles at car parks. Physical properties of the inductive couplers are modelled via 3-D FEM and lumped parameters are used for system studies. Design principles are verified at laboratory scale with a purpose built test stand.}, language = {en} } @inproceedings{HofmannScharfenberg, author = {Hofmann, Gerhard and Scharfenberg, Georg}, title = {Applicability of the ISO 26262 for functional safety for motorbikes}, series = {2014 International Conference on Applied Electronics, 9-10 Sept. 2014, Pilsen, Czech Republic}, booktitle = {2014 International Conference on Applied Electronics, 9-10 Sept. 2014, Pilsen, Czech Republic}, publisher = {IEEE}, doi = {10.1109/AE.2014.7011679}, pages = {107 -- 112}, abstract = {This article deals with the question to what extent the automotive standard for functional safety ISO 26262 is also applicable to motorbikes. It examines thereby, on the one hand where to find comparable criteria between cars and motorbikes from the standpoint of functional safety, and, on the other hand, where differences between the automobile and the motorbike must be considered. It shows the extent to which the safety-related automotive standard is applicable to motorbikes. Furthermore, the differences are determined, which must lead to the consequence of a new "state of the art" and to a new standard for motorbikes. On the example of a light function the new MSIL classification gets applied. In this article, the motorbike is viewed as a whole. For the most parts the standard is also valid for scooters.}, language = {en} } @inproceedings{Schiek, author = {Schiek, Roland}, title = {Self-phase modulation in lithium niobate waveguides}, series = {2014 International Conference Laser Optics, title=Self-phase modulation in lithium niobate waveguides, 30 June-4 July 2014, St. Petersburg, Russia}, booktitle = {2014 International Conference Laser Optics, title=Self-phase modulation in lithium niobate waveguides, 30 June-4 July 2014, St. Petersburg, Russia}, publisher = {IEEE}, doi = {10.1109/LO.2014.6886403}, abstract = {Self-phase modulation in lithium niobate wave-guides with cascaded quadratic and cubic nonlinearities is characterized by comparison of amplitude and phase of input and output pulse envelopes and spectra. Cubic nonlinear susceptibility coefficients of lithium niobate were determined from the measured nonlinear phase shifts.}, language = {en} } @article{Dawoud, author = {Dawoud, Belal}, title = {On the development of an innovative gas-fired heating appliance based on a zeolite-water adsorption heat pump; system description and seasonal gas utilization efficiency}, series = {Applied Thermal Engineering}, volume = {72}, journal = {Applied Thermal Engineering}, number = {2}, publisher = {Elsevier}, doi = {10.1016/j.applthermaleng.2014.09.008}, pages = {323 -- 330}, abstract = {The main objective of this work is to introduce an innovative hybrid heating appliance incorporating a gas condensing boiler and a zeolite-water adsorption heat pump. The condensing boiler is applied to drive the zeolite-water heat pump for the heating base-load and to assist the heat pump in the so called "mixed operation" mode, in which both the heat pump and the condensing boiler are working in series to cover medium heating demands. Peak heating demands are covered by the condensing boiler in the so called "direct heating" mode. The three operation modes of the hybrid heating appliance have been technically described. In addition, the laboratory test conditions for estimating the seasonal heating performance according to the German Guideline VDI 4650-2 have been introduced. For both heating systems 35/28 °C and 55/45 °C, which represent the typical operating conditions of floor and high temperature radiating heating systems in Europe, seasonal heating gas utilization efficiencies of 1.34 and 1.26 have been measured, respectively with a ground heat source. In two field test installations in one-family houses in Germany, the introduced heating appliance showed 27\% more seasonal gas utilization efficiency for heating and domestic hot water production, which is equivalent to a CO2-emission reduction of 20\% compared to the gas condensing boiler technology.}, language = {en} } @article{KuepperArtmannPischingeretal., author = {K{\"u}pper, Carsten and Artmann, Christina and Pischinger, Stefan and Rabl, Hans-Peter}, title = {Lube-Oil Dilution of GDI Engines with Ethanol Fuels}, series = {Auto Tech Review}, volume = {3}, journal = {Auto Tech Review}, number = {3}, publisher = {Springer India}, address = {New Delhi}, doi = {10.1365/s40112-014-0570-5}, pages = {30 -- 35}, language = {en} } @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} } @inproceedings{Mottok, author = {Mottok, J{\"u}rgen}, title = {Migration path for secure and economic smart power grid devices with transitional smart metering support}, series = {2nd Applied Research Conference 2012 (ARC 2012), 25./26. June 2012, Nuremberg}, booktitle = {2nd Applied Research Conference 2012 (ARC 2012), 25./26. June 2012, Nuremberg}, pages = {64 -- 70}, language = {en} } @inproceedings{NickSchorerMottok, author = {Nick, Matthias and Schorer, Michael and Mottok, J{\"u}rgen}, title = {Feasibility Study of a Build System Performing Automated Builds Based on Model-Based Build Descriptions}, series = {2nd Applied Research Conference 2012 (ARC 2012), 25./26. June 2012, Nuremberg}, booktitle = {2nd Applied Research Conference 2012 (ARC 2012), 25./26. June 2012, Nuremberg}, editor = {Mottok, J{\"u}rgen and Ziemann, Olaf}, publisher = {Shaker}, address = {Aachen}, pages = {71 -- 75}, language = {en} } @inproceedings{NonnKalwa, author = {Nonn, Aida and Kalwa, Christoph}, title = {Failure modeling of pipeline X100 Material in temperature transition region}, series = {22nd International Society of Offshore and Polar Engineering 2012 (ISOPE 2012), Rhodes, Greece}, booktitle = {22nd International Society of Offshore and Polar Engineering 2012 (ISOPE 2012), Rhodes, Greece}, abstract = {This paper focuses on the characterization of the fracture performance of X100 material in transition temperature region using both experimental and numerical methods. The ductile fracture has been analyzed using tests on round notched bar specimens and standard fracture mechanics tests performed at room temperature. In previous publications the damage model Gurson-Tvergaard-Needleman (GTN) has been applied and verified by existing experimental data to describe ductile fracture behavior. The brittle fracture and the fracture in temperature transition region have been studied by means of deep and shallow notched SENB specimens at two different temperatures T=- 80°C and -40°C. Besides elastic-plastic analyses to quantify constraint levels for different initial crack configurations at the onset of cleavage fracture, the brittle failure has been described using modified Beremin model. The influence of the stable crack growth on the cleavage failure probability in temperature transition region has been captured by coupling the ductile fracture model (GTN) with the modified Beremin model. Finally, examples have been presented for the practical application of the numerical results on the fracture assessment of the flawed high-strength pipelines.}, language = {en} } @inproceedings{KofianiNonnWierzbickietal., author = {Kofiani, Kirki and Nonn, Aida and Wierzbicki, Tomasz and Kalwa, Christoph and Walters, Carey}, title = {Experiments and fracture modeling of high-strength pipelines for high and low stress triaxiality}, series = {22nd International Society of Offshore and Polar Engineering 2012 (ISOPE 2012), Rhodes, Greece, June 2012}, booktitle = {22nd International Society of Offshore and Polar Engineering 2012 (ISOPE 2012), Rhodes, Greece, June 2012}, abstract = {This paper provides results from a comprehensive study on mechanical characterization of high-strength pipeline steel, grade X100 using experimental and numerical methods. The material was characterized for anisotropic plasticity, fracture initiation for various states of stress, (pre-cracked) fracture toughness and uncracked ductility. The experimental program included tests on flat butterfly-shaped, central hole, notched and circular disk specimens for low stress triaxiality levels; as well as tests on round notched bar specimens and SENT fracture mechanics tests, for high values of stress triaxiality. This program covered a wide range of stress conditions and demonstrated its effect on the material resistance. Parallel to the experimental study, detailed numerical investigations were carried out to simulate all different experimental tests. Using an inverse method, a 3-parameter calibration was performed on the Modified Mohr-Coulomb (MMC) fracture model. Subsequently, the predictive capabilities of the MMC were evaluated by the comparison to the fracture toughness tests results, used extensively in the pipeline industry. The capabilities of the MIT fracture model have been demonstrated on an example of high strength offshore steel, X100. The outcome of this study was not only to provide, the overall characterization of the fracture behavior of this material as an example, but also to present the methodology on how to use the MMC model as a practical tool in pipeline design.}, language = {en} } @inproceedings{BogomolovKralHaumeretal., author = {Bogomolov, Maxim and Kral, Christian and Haumer, Anton and Lomonova, Elena}, title = {Modeling of permanent magnet synchronous machine with fractional slot windings}, series = {Proceedings IECON 2012 - 38th Annual Conference on IEEE Industrial Electronics Society ; Ecole de Technologie Superieure de Montreal, Universite du Quebec Montreal, Canada 25 - 28 October, 2012}, booktitle = {Proceedings IECON 2012 - 38th Annual Conference on IEEE Industrial Electronics Society ; Ecole de Technologie Superieure de Montreal, Universite du Quebec Montreal, Canada 25 - 28 October, 2012}, publisher = {IEEE}, address = {Piscataway, NJ}, isbn = {978-1-4673-2421-2}, issn = {1553-572X}, doi = {10.1109/IECON.2012.6388912}, pages = {1894 -- 1899}, abstract = {This paper focuses on simulation of permanent magnet synchronous machine (PMSM) with fractional-slot windings (FSW) in Modelica. Modeling of the electrical machines with object-oriented approach is shortly described, and a new Modelica library for simulation of electrical machines is introduced. The results of simulation of PMSMs with fractional slot windings are presented and explained. Special attention is paid to the higher harmonics and subharmonics produced by the winding and their influence on machine operation.}, language = {en} } @article{HaumerKralVukovicetal., author = {Haumer, Anton and Kral, Christian and Vukovic, Vladimir and David, Alexander and Hettfleisch, Christian and Huzsvar, Attila}, title = {A Parametrization Scheme for High Performance Thermal Models of Electric Machines using Modelica}, series = {IFAC Proceedings Volumes}, volume = {45}, journal = {IFAC Proceedings Volumes}, number = {2}, publisher = {Elsevier}, address = {Amsterdam}, issn = {1474-6670}, doi = {10.3182/20120215-3-AT-3016.00187}, pages = {1058 -- 1062}, abstract = {Thermal models offer great advantages for enhancement of design, protection and control of electric machines. Detailed thermal models take a great number of time constants into account and provide accurate prediction of the temperatures. However, to parameterize such models detailed geometric data are needed. Whenever such detailed information is not available, or the performance of the detailed models is not satisfying, simplified thermal models as described in this paper are advantageous. The calculation of parameters is described in detail, in order to achieve best accordance with temperatures obtained from measurements or from simulations with detailed thermal models. Thermal resistances are calculated from end temperatures of a test run with constant load (and known losses). Thermal capacitances are obtained using optimization to minimize deviation of simulated and measured temperatures during the whole test run. The thermal model of an asynchronous induction machine with squirrel cage is coupled with an electrical model of the drive. For validation, simulation results of an optimally parameterized simplified model are compared with temperatures obtained by simulation of a detailed thermal model, which in turn has been validated against measurement results, both for continuous duty S1 and intermittent duty S6 (6 minutes no-load followed by 4 minutes of 140\% nominal load). The deviations are not more than 4 K which is quite satisfying.}, language = {en} } @inproceedings{HaumerKral, author = {Haumer, Anton and Kral, Christian}, title = {Motor Management of Permanent Magnet Synchronous Machines}, series = {Proceedings of the 9th International MODELICA Conference; September 3-5; 2012; Munich; Germany}, booktitle = {Proceedings of the 9th International MODELICA Conference; September 3-5; 2012; Munich; Germany}, editor = {Otter, Martin and Zimmer, Dirk}, publisher = {Link{\"o}ping University Electronic Press}, isbn = {978-91-7519-826-2}, issn = {1650-3686}, doi = {10.3384/ecp12076159}, pages = {159 -- 166}, abstract = {Two state-of-the-art machine designs are mainly used in recent electric and hybrid electric vehicles: asynchronous induction machines with squirrel cage which are robust but need a current component to excite the magnetic field; and permanent magnet synchronous machines which rely on somehow more sensible parts but the magnets are able to excite a magnetic field without current. However; if speed gets high enough to reach the field weakening range; for both machine the field oriented control has to prescribe a field current sufficient to reduce the field not to exceed the voltage limits of the stator circuit. Especially for the permanent magnet synchronous machine this paper investigates whether it is possible to determine an optimal field current for every operation point to minimize either total current consumption or losses.}, language = {en} } @inproceedings{KralHaumerBogomolovetal., author = {Kral, Christian and Haumer, Anton and Bogomolov, Maxim and Lomonova, Elena}, title = {Harmonic wave model of a permanent magnet synchronous machine for modeling partial demagnetization under short circuit conditions}, series = {2012 XXth International Conference on Electrical Machines (ICEM 2012) ; Marseille, France, 2 - 5 September 2012}, booktitle = {2012 XXth International Conference on Electrical Machines (ICEM 2012) ; Marseille, France, 2 - 5 September 2012}, publisher = {IEEE}, address = {Piscataway, NJ}, isbn = {978-1-4673-0142-8}, doi = {10.1109/ICElMach.2012.6349880}, pages = {295 -- 301}, abstract = {This paper proposes a multi domain physical model of permanent magnet synchronous machines, considering electrical, magnetic, thermal and mechanical effects. For each component of the model, the main wave as well as lower and higher harmonic wave components of the magnetic flux and the magnetic potential difference may be considered. The permanent magnets are modeled as discrete azimuthal segments in order to consider possible partial demagnetization effects. For each magnet segment a linearized temperature dependent B-H curve is considered. The main advantage of the presented model is that time transient operational behavior of a permanent magnet synchronous machine can be considered under various electrical, magnetic, thermal and mechanical conditions. The electromagnetic condition of surface magnet machine is compared with finite element analysis.}, language = {en} } @inproceedings{KralHaumerLee, author = {Kral, Christian and Haumer, Anton and Lee, Sang Bin}, title = {Robust thermal model for the estimation of rotor cage and stator winding temperatures of induction machines}, series = {2012 XXth International Conference on Electrical Machines ; Marseille, France, 02.- 05.09.2012}, booktitle = {2012 XXth International Conference on Electrical Machines ; Marseille, France, 02.- 05.09.2012}, publisher = {IEEE}, address = {Piscataway, NJ}, isbn = {978-1-4673-0142-8}, doi = {10.1109/ICElMach.2012.6350127}, pages = {1810 -- 1816}, abstract = {In this paper a new model for the estimation of the stator winding and rotor cage temperatures of induction machines is presented. This model can be used in series applications of machines operated under dynamic load conditions where stator and rotor temperature shall be monitored. The proposed model relies on a simplified lumped element thermal equivalent circuit model where the stator core temperature serves as input quantity. The great advantage of this model is that it covers ambient and cooling conditions inherently. This leads to great simplicity and robustness. The parametrization and validation of the model through experimental data is presented. Advantages, drawbacks and possible implementations are discussed.}, language = {en} } @inproceedings{KralHaumerLee, author = {Kral, Christian and Haumer, Anton and Lee, Sang Bin}, title = {Innovative thermal model for the estimation of permanent magnet and stator winding temperatures}, series = {2012 IEEE Energy Conversion Congress and Exposition (ECCE 2012) ; Raleigh, NC, USA 15.09.-20.09.2012}, booktitle = {2012 IEEE Energy Conversion Congress and Exposition (ECCE 2012) ; Raleigh, NC, USA 15.09.-20.09.2012}, publisher = {IEEE}, address = {Piscataway, NJ}, isbn = {978-1-4673-0803-8}, issn = {2329-3721}, doi = {10.1109/ECCE.2012.6342386}, pages = {2704 -- 2711}, abstract = {In this paper an innovative thermal model for the determination of the temperatures of the permanent magnets and stator windings is presented. This model relies on one temperature sensor located in the stator core of the machine. The estimated stator winding and permanent magnet temperatures are determined by a simplified thermal lumped element network model with only two time constants. Due to the structure of the model and the measured stator core temperature the proposed thermal model is very robust. Distortion of the cooling circuit are inherently sensed such that the model can be used for the online prediction of temperatures. Experimental results based on an interior permanent magnet synchronous machine are presented to validate the presented model.}, language = {en} } @techreport{MichaelSternerMareikeJentschUweHolzhammer, author = {Michael Sterner, and Mareike Jentsch, and Uwe Holzhammer,}, title = {Energiewirtschaftliche und {\"o}kologische Bewertung eines Windgas-Angebotes}, publisher = {Fraunhofer Institute for Energy Economics and Energy System Technology}, address = {Kassel}, doi = {10.13140/RG.2.2.25093.68328}, abstract = {In this technical report, (1) the benefits of the new technology for future energy supply are discussed, (2) the climate protection effect of wind gas is discussed, and (3) a reasonable use of wind energy for gas generation is analyzed. In particular, windgas in the heat market is discussed in the utilization cascade of wind energy. The new "power-to-gas" concept opens up completely new possibilities for the integration of renewable energies and for coupling the electricity and gas grids. The Sabatier process, which has been known for 100 years, was first developed for this purpose in 2008 under the leadership of the Center for Solar Energy and Hydrogen Research and Fraunhofer IWES (formerly ISET) with electrolysis to create the "power-to-gas" concept for energy storage. A first pilot plant was built by ZSW Stuttgart on behalf of SolarFuel in 2009. This plant proves the technical feasibility of the new technology. Renewable gas is stored, transported and used as required as control and reserve energy via reconversion, e.g. in combined cycle power plants. In this way, decentrally generated renewable electricity is converted into a CO2 -neutral energy carrier with high energy density. The key advantage of renewable methane is the use of existing infrastructure such as gas grids, gas storage and end-use equipment for the integration of renewable energy. Technologies for natural gas are state of the art and commercially available. Methane also has three times the energy density of hydrogen.}, language = {en} } @inproceedings{NonnKalwa, author = {Nonn, Aida and Kalwa, Christoph}, title = {The effect of microstructure, strain hardening and strain rate on the fracture behavior of high strength pipeline steels}, series = {2nd International Conference on Material Modelling (ICMM2), 31th August - 2nd September, 2011 at Mines Paris Tech, France}, booktitle = {2nd International Conference on Material Modelling (ICMM2), 31th August - 2nd September, 2011 at Mines Paris Tech, France}, language = {en} } @techreport{OPUS4-2062, title = {Energienutzungsplan f{\"u}r die Gemeinde Sinzing}, editor = {Neuleitner, Nikolaus and Steffens, Oliver}, organization = {Hochschule f{\"u}r ANgewandte Wissenschaften Regensburg}, language = {de} } @inproceedings{HongHyunKangetal., author = {Hong, Jongman and Hyun, Doosoo and Kang, Tae-june and Lee, Sang Bin and Kral, Christian and Haumer, Anton}, title = {Detection and classification of rotor demagnetization and eccentricity faults for PM synchronous motors}, series = {2011 IEEE Energy Conversion Congress and Exposition (ECCE 2011) : Energy conversion innovation for a clean energy future ; Phoenix, Arizona, USA, 17.-22.09.2011}, booktitle = {2011 IEEE Energy Conversion Congress and Exposition (ECCE 2011) : Energy conversion innovation for a clean energy future ; Phoenix, Arizona, USA, 17.-22.09.2011}, publisher = {IEEE}, address = {Piscataway, NJ}, isbn = {978-1-4577-0542-7}, issn = {2329-3721}, doi = {10.1109/ECCE.2011.6064103}, pages = {2512 -- 2519}, abstract = {Condition monitoring of rotor problems such as demagnetization and eccentricity in permanent magnet synchronous motors (PMSM) is essential for guaranteeing high motor performance, efficiency, and reliability. However, there are many limitations to the off-line and on-line methods currently used for PMSM rotor quality assessment. In this paper, an inverter-embedded technique for automated detection and classification of PMSM rotor faults is proposed as an alternative. The main concept is to use the inverter to perform a test whenever the motor is stopped, to detect rotor faults independent of operating conditions or load torque oscillations, which is not possible with motor current signature analysis (MCSA). The d-axis is excited with a dc+ac signal, and the variation in the inductance pattern due to the change in the degree of magnetic saturation caused by demagnetization or eccentricity is observed for fault detection. An experimental study on a 7.5kW PMSM verifies that demagnetization and eccentricity can be detected and classified independent of the load with high sensitivity.}, language = {en} } @inproceedings{HongLeeKraletal., author = {Hong, Jongman and Lee, Sang Bin and Kral, Christian and Haumer, Anton}, title = {Detection of airgap eccentricity for permanent magnet synchronous motors based on the d-axis inductance}, series = {8th IEEE International Symposium on Diagnostics for Electric Machines, Power Electronics \& Drives (SDEMPED), 2011 // 05. - 08.09.2011, Bologna, Italy}, booktitle = {8th IEEE International Symposium on Diagnostics for Electric Machines, Power Electronics \& Drives (SDEMPED), 2011 // 05. - 08.09.2011, Bologna, Italy}, publisher = {IEEE}, address = {Piscataway, NJ}, isbn = {978-1-4244-9301-2}, doi = {10.1109/DEMPED.2011.6063651}, pages = {378 -- 384}, abstract = {The majority of the work performed for detecting eccentricity faults for permanent magnet synchronous motors (PMSM) focus on motor current signature analysis (MCSA), as it provides continuous on-line monitoring with existing current sensors. However, MCSA cannot be applied under nonstationary conditions and cannot distinguish faults with load torque oscillations, which are limitations for many PMSM drive applications. In this paper, it is shown that the d-axis inductance, L d , decreases with increase in the severity of eccentricity due to the change in the degree of magnetic saturation, and it is proposed as a new fault indicator. The inverter can be used to perform a standstill test automatically whenever the motor is stopped, to measure L d for eccentricity testing independent of load variations or oscillations, which is not possible with MCSA. An FE and experimental study on a 10hp PMSM verifies that eccentricity can be detected independent of the load with high sensitivity and reliability.}, language = {en} } @inproceedings{HaumerKral, author = {Haumer, Anton and Kral, Christian}, title = {Modeling a Mains connected PWM Converter with Voltage-Oriented Control}, series = {Proceedings of the 8th International Modelica Conference, Technical Univeristy, Dresden, Germany, 20.-22.03.2011}, booktitle = {Proceedings of the 8th International Modelica Conference, Technical Univeristy, Dresden, Germany, 20.-22.03.2011}, publisher = {Link{\"o}ping University Electronic Press}, doi = {10.3384/ecp11063388}, pages = {388 -- 397}, abstract = {The majority of industrial controlled induction machine drives are connected to the mains via a diode bridge. However; if reduction of harmonic currents and / or regenerative operation is desired; replacing the diode bridge by an active front-end (AFE) is required. This paper describes two models of an AFE: a power balance model disregarding switching effects; and an ideal switching model of a pulse width modulation (PWM) converter. Both models are controlled utilizing space phasors in a voltage oriented reference frame. Voltage oriented control (VOC) of the mains converter can be compared with field oriented control (FOC) of a machine converter. Design and parametrization of the main parts—synchronization with mains voltage; current controller and DC voltage controller—are described in detail. Additionally; simulation results proving the implementation and demonstrating possible investigations as well as an outlook on further enhancements are presented.}, language = {en} } @inproceedings{KralHaumer, author = {Kral, Christian and Haumer, Anton}, title = {The New FundamentalWave Library for Modeling Rotating Electrical Three Phase Machines}, series = {Proceedings of the 8th International Modelica Conference; March 20th-22nd; Technical Univeristy; Dresden; Germany}, booktitle = {Proceedings of the 8th International Modelica Conference; March 20th-22nd; Technical Univeristy; Dresden; Germany}, publisher = {University Electronic Press}, address = {Link{\"o}ping}, isbn = {978-91-7393-096-3}, issn = {1650-3686}, doi = {10.3384/ecp11063170}, pages = {170 -- 179}, abstract = {This paper introduces the new FundemantalWave library which is included in the Modelica Standard Library 3.2. The presented Modelica package provides models and components of rotating electrical three phase machines. The presented electrical machine models are fully compatible with the original Machines library of the electrical domain but rely on the concept of the magnetic potential and magnetic flux fundamental waves. In this article; the connector concept; the components and electric machine models of the FundemantalWave package will be explained. Additionally; the didactic advantages and the flexibility of the proposed package in with respect to considering more enhanced and sophisticated effects will be discussed.}, language = {en} } @incollection{KralHaumer, author = {Kral, Christian and Haumer, Anton}, title = {Object Oriented Modeling of Rotating Electrical Machines}, series = {Advances in Computer Science and Engineering}, booktitle = {Advances in Computer Science and Engineering}, editor = {Schmidt, Matthias}, publisher = {IntechOpen}, isbn = {978-953-307-173-2}, doi = {10.5772/15898}, pages = {135 -- 160}, language = {en} } @inproceedings{BaeumlHaumerKapelleretal., author = {B{\"a}uml, T. and Haumer, Anton and Kapeller, Hansj{\"o}rg and Starzinger, J. and Farzi, P.}, title = {Impact of inverter pulse inhibition on the high-voltage supply system of an electric vehicle — A simulative approach}, series = {2011 IEEE Vehicle Power and Propulsion Conference (VPPC 2011) : Powering sustainable transportation ; Chicago, Illinois, USA, 06. - 09.09.2011}, booktitle = {2011 IEEE Vehicle Power and Propulsion Conference (VPPC 2011) : Powering sustainable transportation ; Chicago, Illinois, USA, 06. - 09.09.2011}, publisher = {IEEE}, address = {Piscataway, NJ}, isbn = {978-1-61284-248-6}, doi = {10.1109/VPPC.2011.6043159}, pages = {1 -- 5}, abstract = {This paper deals with a simulative approach for investigating the impact of inverter pulse inhibition during field weakening operation of permanent magnet synchronous machines and asynchronous induction machines. The modelling and simulation language Modelica is used to design models for the vehicle, the electric machine and the inverter in different abstraction levels. It is shown that when using a permanent magnet synchronous machine, a sudden breakdown of the field weakening current causes induction of high voltages in the stator windings. Hence, the electric system of the vehicle has to be protected against the resulting high currents. Furthermore precautions have to be taken to avoid dangerous driving conditions because of high braking torques in an inverter fault operation mode. In the case of the asynchronous induction machine an inverter pulse inhibition poses no big problem, neither for the electric system of the vehicle, nor the driver.}, language = {en} }