TY - CHAP A1 - Kral, Christian A1 - Haumer, Anton A1 - Bogomolov, Maxim A1 - Lomonova, Elena T1 - Harmonic wave model of a permanent magnet synchronous machine for modeling partial demagnetization under short circuit conditions T2 - 2012 XXth International Conference on Electrical Machines (ICEM 2012) ; Marseille, France, 2 - 5 September 2012 N2 - 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. KW - demagnetization KW - harmonic analysis KW - magnetic fields KW - magnetic flux KW - magnetic potential difference KW - permanent magnet synchronous machine KW - reluctance KW - segmentation KW - temperature Y1 - 2012 SN - 978-1-4673-0142-8 U6 - https://doi.org/10.1109/ICElMach.2012.6349880 SP - 295 EP - 301 PB - IEEE CY - Piscataway, NJ ER - TY - CHAP A1 - Kral, Christian A1 - Haumer, Anton A1 - Lee, Sang Bin T1 - Robust thermal model for the estimation of rotor cage and stator winding temperatures of induction machines T2 - 2012 XXth International Conference on Electrical Machines ; Marseille, France, 02.- 05.09.2012 N2 - 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. KW - asynchronous machines KW - Cooling KW - dynamic load KW - equivalent circuits KW - lumped element thermal equivalent circuit model KW - Rotors KW - squirrel cage induction machine KW - stators KW - temperature estimation Y1 - 2012 SN - 978-1-4673-0142-8 SN - 978-1-4673-0143-5 SN - 978-1-4673-0141-1 U6 - https://doi.org/10.1109/ICElMach.2012.6350127 SP - 1810 EP - 1816 PB - IEEE CY - Piscataway, NJ ER - TY - CHAP A1 - Kral, Christian A1 - Haumer, Anton A1 - Lee, Sang Bin T1 - Innovative thermal model for the estimation of permanent magnet and stator winding temperatures T2 - 2012 IEEE Energy Conversion Congress and Exposition (ECCE 2012) ; Raleigh, NC, USA 15.09.-20.09.2012 N2 - 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. KW - Cooling KW - dynamic load KW - lumped element thermal equivalent circuit model KW - permanent magnet machines KW - permanent magnet synchronous machine KW - stators KW - synchronous machines KW - temperature estimation KW - temperature sensors KW - variable speed Y1 - 2012 SN - 978-1-4673-0803-8 SN - 978-1-4673-0802-1 SN - 978-1-4673-0801-4 U6 - https://doi.org/10.1109/ECCE.2012.6342386 SN - 2329-3721 SN - 2329-3748 SP - 2704 EP - 2711 PB - IEEE CY - Piscataway, NJ ER - TY - CHAP A1 - Kral, Christian A1 - Haumer, Anton T1 - The New FundamentalWave Library for Modeling Rotating Electrical Three Phase Machines T2 - Proceedings of the 8th International Modelica Conference; March 20th-22nd; Technical Univeristy; Dresden; Germany N2 - 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. KW - fundamental wave KW - Modelica Standard Library MSL KW - Rotating electrical three phase machines KW - time transients Y1 - 2011 SN - 978-91-7393-096-3 U6 - https://doi.org/10.3384/ecp11063170 SN - 1650-3686 SN - 1650-3740 SP - 170 EP - 179 PB - University Electronic Press CY - Linköping ER - TY - CHAP A1 - Kral, Christian A1 - Haumer, Anton A1 - Grabner, Christian ED - Ao, Sio-Iong ED - Gelman, Len T1 - Determination of Consistent Induction Motor Parameters T2 - Electronic Engineering and Computing Technology N2 - From the rating plate data of an induction motor the nominal efficiency can be determined. Without detailed knowledge of equivalent circuit parameters, partial load behavior cannot be computed. Therefore, a combined calculation and estimation scheme is presented, where the consistent parameters of an equivalent circuit are elaborated, exactly matching the nominal operating point. From these parameters part load efficiencies can be determined. KW - consistent parameters KW - iduction motor KW - partial load efficiency Y1 - 2010 SN - 978-90-481-8775-1 SN - 978-90-481-8776-8 U6 - https://doi.org/10.1007/978-90-481-8776-8_7 VL - 60 SP - 71 EP - 80 PB - Springer CY - Dordrecht ER - TY - CHAP A1 - Kral, Christian A1 - Haumer, Anton A1 - Grabner, Christian ED - Ao, Sio-Iong ED - Gelman, Len T1 - Broken Rotor Bars in Squirrel Cage Induction Machines – Modeling and Simulation T2 - Electronic Engineering and Computing Technology N2 - This paper presents a physical model of a squirrel cage induction machine with rotor topology. The machine is modeled in Modelica, an object oriented multi physical modeling system. The presented machine model is used to investigate electrical rotor asymmetries in induction machines. For the case of a single broken rotor bar a simulation model is compared with measurement results. KW - broken rotor bar KW - induction machines KW - Modelica KW - rotor asymmetries KW - squirrel cage Y1 - 2010 SN - 978-90-481-8775-1 SN - 978-90-481-8776-8 U6 - https://doi.org/10.1007/978-90-481-8776-8_8 SP - 81 EP - 91 PB - Springer CY - Dordrecht ER - TY - CHAP A1 - Kral, Christian A1 - Haumer, Anton ED - Schmidt, Matthias T1 - Object Oriented Modeling of Rotating Electrical Machines T2 - Advances in Computer Science and Engineering Y1 - 2011 SN - 978-953-307-173-2 SN - 978-953-51-5990-2 U6 - https://doi.org/10.5772/15898 SP - 135 EP - 160 PB - IntechOpen ER - TY - CHAP A1 - Hopfensperger, Bernhard A1 - Daubner, Andreas A1 - Herrmann, Fabian A1 - Hopkins, Andrew A1 - Mellor, Phil T1 - Investigation of Shifted PWM Methods for a Dual Three-Phase System to Reduce Capacitor RMS Current T2 - PCIM Europe Digital Days 2020: International Exhibition and Conference for Power Electronics, Intelligent Motion, Renewable Energy and Energy Management: 07.-08.07.2020, Online [proceedings] N2 - Mild hybrid automotive topologies containing a 48V high power (>15 kW) electric drive system demand a high integration of power electronics and electrical machine. A multi-phase motor winding topology helps to keep the per-phase operating currents to a reasonable level. Close integration and multi-phase system have led to a drive system with dual 3-phase systems supplied by a common 48V DC-link, which allows to shift PWM patterns for reduction of DC-link capacitor ripple current and size. This paper derives some basic rules for combinations of common PWM methods for dual 3-phase systems without magnetic cross-coupling. Experimental measurements verify simulated results. KW - Elektroantrieb KW - dual three phase system Y1 - 2020 UR - https://ieeexplore.ieee.org/document/9177989 SN - 978-3-8007-5245-4 SP - 124 EP - 131 PB - VDE-Verlag CY - Berlin, Offenbach ER - TY - CHAP A1 - Grauvogl, Dominik A1 - Stauder, Peter A1 - Hopfensperger, Bernhard A1 - Gerling, Dieter T1 - Multiphysics Design of a Wound Field Synchronous Machine with Magnetic Asymmetry T2 - Proceedings of the 2021 IEEE International Electric Machines & Drives Conference (IEMDC): 17-20 May 2021, Hartford, CT, USA N2 - In this paper a multiphysics development method is used for designing a novel wound field synchronous machine of the future generation of high voltage traction drives. This method covers the domains of electromagnetics, the mechanical strength, thermal behavior and the magnetic noise. It is shown that the proposed novel asymmetric design with a circular flux barrier in combination with an asymmetric pole offset is fulfilling the requirements according to performance and torque ripple. A fatigue strength rotor mechanic concept is included. A hybrid cooling concept consisting of a water jacket cooled stator and air cooled rotor ensures the needed continuous power. Unacceptable noise levels are excluded by investigating the equivalent radiated power (ERP) level due to radial forces in the air gap. Finally, the multi-physical workflow resulted in a fully developed component with a high degree of maturity. KW - air cooling KW - wound field synchronous machine KW - cooling concept KW - fatigue limit KW - flux barrier Y1 - 2021 U6 - https://doi.org/10.1109/IEMDC47953.2021.9449564 ER - TY - CHAP A1 - Grauvogl, Dominik A1 - Krabinski, Jeffrey A1 - Stauder, Peter A1 - Hopfensperger, Bernhard A1 - Gerling, Dieter T1 - NVH Comparison of a Novel Wound Field Synchronous Machine with Magnetic Asymmetry with a PSM for a HV Electric Drive T2 - 2021 JSAE Annual Congress (Spring) Proceedings; online meeting (No.76-21) N2 - This paper shows how magnetic noises can be reduced with a wound field synchronous machine (WFSM) with magnetic asymmetry compared to a permanent magnet synchronous machine (PSM), operating at base speed range and full load. In order to reproduce a real noise behavior, the two rotor types are operated in a complete electric drive unit (EDU) consisting of an electric motor, gearbox, inverter and overall housing. In the concept study, the noise characteristics of the two electric machines is evaluated and compared via mechanical finite element method (FEM) simulations using the equivalent radiated power (ERP) level and Campbell diagrams. Furthermore, it is shown that critical frequency orders can already be identified by the analysis of the magnetic force density from the electromagnetic design without computationally intensive ERP calculations. In this context, the ERP investigations have shown that the unique feature of the magnetically asymmetric WFSM is the reduction of the slot harmonics. At the current state of the art, the slot harmonics can only be reduced with a rotor skewing. The disadvantage of this is a reduction in performance and a more expensive production. It is also remarkable that the magnetic asymmetry reduces the slot harmonics more than the rotor skewing in the PSM. In addition, both machines are still considered with a short-pitched stator winding to optimize the overall noise level by reducing the 24th frequency order. KW - Elektroantrieb KW - Synchronmaschine KW - traction drive system KW - NVH KW - e-axle KW - magnetic asymmetry Y1 - 2021 UR - https://tech.jsae.or.jp/paperinfo/en/content/p202101.343/ PB - JSAE ER -