@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} } @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} } @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{BaeumlHaumerKapelleretal., author = {B{\"a}uml, T. and Haumer, Anton and Kapeller, H. 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} } @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{JungreuthmayerBaumlWinteretal., author = {Jungreuthmayer, C. and Bauml, T. and Winter, O. and Ganchev, M. and Kapeller, H. and Haumer, Anton and Kral, Christian}, title = {Heat and fluid flow analysis of an internal permanent magnet synchronous machine by means of computational fluid dynamics}, series = {2011 IEEE International Electric Machines \& Drives Conference (IEMDC 2011) ; Niagara Falls, Ontario, Canada, 15 - 18 May 2011}, booktitle = {2011 IEEE International Electric Machines \& Drives Conference (IEMDC 2011) ; Niagara Falls, Ontario, Canada, 15 - 18 May 2011}, publisher = {IEEE}, address = {Piscataway, NJ}, isbn = {978-1-4577-0060-6}, doi = {10.1109/IEMDC.2011.5994651}, pages = {515 -- 520}, abstract = {This paper presents a comprehensive computational fluid (CFD) model of a radial flux permanent magnet synchronous machine with interior magnets. In the CFD model the water jacket cooling and a simplified model of the topology of the distributed stator winding are considered. The heat sources of the CFD model are determined from a finite element analysis of the machine. The numerically determined temperature distributions of the machine are compared with measurement results from sensors located both in the stator and rotor. The particular focus of this paper is the analysis of the temperatures and the heat flow in the air gap and from the stator winding head and the rotor to the inner air.}, language = {en} }