TY - JOUR A1 - Haumer, Anton A1 - Kral, Christian A1 - Vukovic, Vladimir A1 - David, Alexander A1 - Hettfleisch, Christian A1 - Huzsvar, Attila T1 - A Parametrization Scheme for High Performance Thermal Models of Electric Machines using Modelica JF - IFAC Proceedings Volumes N2 - 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. KW - Electric machines KW - Induction machines KW - Thermal models KW - Model reduction KW - Parameter identification KW - Parameter optimization Y1 - 2012 U6 - https://doi.org/10.3182/20120215-3-AT-3016.00187 SN - 1474-6670 VL - 45 IS - 2 SP - 1058 EP - 1062 PB - Elsevier CY - Amsterdam ER - TY - CHAP A1 - Kapeller, Hansjörg A1 - Haumer, Anton A1 - Kral, Christian A1 - Grabner, Christian ED - Ao, Sio-Iong ED - Gelman, Len T1 - Different Designs of Large Chipper Drives T2 - Electronic Engineering and Computing Technology N2 - This paper presents two simulation models for two variants of a large chipper drive used in a paper mill. If a slip ring induction motor is used, the impact of a rotor circuit rheostat with respect to starting behavior and heavy duty load impulses can be examined. Furthermore a speed controlled squirrel cage induction machine will be investigated. The modeling language for both drives is Modelica. The simulation results for both drives are compared and discussed. KW - induction motor KW - load impulses KW - slip ring KW - speed control 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_9 SP - 93 EP - 104 PB - Springer CY - Dordrecht 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 - JOUR A1 - Kral, Christian A1 - Haumer, Anton A1 - Grabner, Christian T1 - Consistent Induction Motor Parameters for the Calculation of Partial Load Efficiencies by Means of an Advanced Simulation Model JF - Engineering Letters 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 - Induction motor KW - consistent parameters KW - partial load efficiency Y1 - 2010 SN - 1816-0948 SN - 1816-093X VL - 18 IS - 1 CY - Hong Kong ER - TY - CHAP A1 - Grabner, Christian A1 - Gragger, Johannes V. A1 - Kapeller, Hansjörg A1 - Haumer, Anton A1 - Kral, Christian ED - Ao, Sio-Iong ED - Gelman, Len T1 - Sensorless PM-Drive Aspects T2 - Electronic Engineering and Computing Technology N2 - The development procedure of permanent magnet drives for sensor less operation beginning from standstill under overload conditions has to consider different design aspects coevally. First, the robust rotor position sensing by test signal enforces a design with a strongly different behavior of the spatial dq-oriented differential inductance values. Therefore, the interior rotor magnet array arrangement is from principle predestinated for the controlled sensor less mode including standstill. Fortunately, in order to reduce costs, the distinct reluctance torque capability of such interior magnet arrangement is additionally used for a significantly increased torque by applying a pre-oriented stator current space vectors within the quasi-steady control. KW - inductance modeling KW - machine design KW - nonlinear saturation effects KW - Sensorless vector control 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_3 SP - 25 EP - 35 PB - Springer CY - Dordrecht ER - TY - CHAP A1 - Haumer, Anton A1 - Kral, Christian T1 - Enhancements of Electric Machine Models: The EMachines Library T2 - Proceedings of the 11th International Modelica Conference, Versailles, France, September 21-23, 2015 N2 - Transient models of multi phase electric machines are already implemented in the Modelica Standard Library (MSL). However, advanced effects like saturation and skin effect are not taken into account. As an extension to the MSL models, the new EMachines library is presented. This package will be released as a supplemental library to the commercial EDrives library. The particular focus of this paper is on the deep bar effect of induction machines. A comparison of simulation results demonstrates the influence of the skin effect on the operational behavior of the machines. At the end of this publication further developments of the EMachines library will be outlined. KW - multi phase electric machines KW - induction machines KW - squirrel cage KW - deep bar effect KW - skin effect Y1 - 2015 U6 - https://doi.org/10.3384/ecp15118509 VL - 118 SP - 509 EP - 515 PB - Linköping University Electronic Press ER - TY - CHAP A1 - Brkic, Jovan A1 - Ceran, Muaz A1 - Elmoghazy, Mohamed A1 - Kavlak, Ramazan A1 - Haumer, Anton A1 - Kral, Christian T1 - Open Source PhotoVoltaics Library for Systemic Investigations T2 - Proceedings of the 13th International Modelica Conference, March 4-6, 2019, Regensburg, Germany N2 - For the planning of photovoltaic power plants standard software tools are used. Most of these software tools use statistical solar data to determine the overall energy harvest of a photovoltaic plant over one year. The calculations rely on stationary location and ideal boundary conditions, e.g., constant ambient temperature. Even though, for example, shadowing may be considered by standard software, the investigation of untypical configurations and problems cannot be performed by such software, as most configurations cannot be changed by the user. The presented PhotoVoltaics library was developed with the intention to provide a flexible framework for standard and non-standard problems. Particularly, the PhotoVoltaics library can be coupled with other Modelica libraries to perform systemic investigations. An application library, PhotoVoltaics_TGM, is provided as add-on, where measured data of two photovoltaic pants of the TGM in Vienna can be compared with simulation results. This add-on library serves as validation of the PhotoVoltaics library. KW - CELL KW - converter KW - data sheet KW - irradiance KW - maximum power tracking KW - module KW - Photovoltaics KW - plant KW - terrestrial solar model Y1 - 2019 U6 - https://doi.org/10.3384/ecp1915741 SP - 41 EP - 50 PB - Linköing University Electronic Press ER - TY - CHAP A1 - Eberhart, Philip A1 - Chung, Tek Shan A1 - Haumer, Anton A1 - Kral, Christian T1 - Open Source Library for the Simulation of Wind Power Plants T2 - Proceedings of the 11th International Modelica Conference, Versailles, France, September 21-23, 2015 N2 - This paper presents the new open source Modelica libraryWindPowerPlants. For the economic assessment of either a wind power plant or an entire wind park, the accurate prediction of the energy output is essential. Such prediction is usually performed by means of calculations based on statistical wind data. The proposed WindPowerPlants library is capable of assessing the energy output both for statistical and real wind data based on time domain simulations. In the presented version of the library wind turbine models are modeled with pitch control. The generator models have variable speed and an optional connector to the mains. The entire library is based on power balance conditions and losses are fully neglected. Yet, the library can be extended towards more detailed models considering different types of losses. The structure and components of the library are presented. Simulations examples are shown and compared with reference data. The applicability of the proposed WindPowerPlants library is demonstrated and possible enhancements are discussed. KW - variable speed KW - pitch control KW - Wind power pants KW - energy KW - statistical wind data KW - power Y1 - 2015 U6 - https://doi.org/10.3384/ecp15118929 SP - 929 EP - 936 CY - Linköping ER - TY - JOUR A1 - Kral, Christian A1 - Haumer, Anton A1 - Lee, Sang Bin T1 - A Practical Thermal Model for the Estimation of Permanent Magnet and Stator Winding Temperatures JF - IEEE Transactions on Power Electronics N2 - 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. KW - cooling KW - lumped element thermal equivalent circuit model KW - magnetic cores KW - permanent magnet machines KW - permanent magnet synchronous machine KW - stators KW - synchronous machines KW - temperature estimation KW - variable speed KW - dynamic load Y1 - 2014 U6 - https://doi.org/10.1109/TPEL.2013.2253128 SN - 1941-0107 SN - 0885-8993 VL - 29 IS - 1 SP - 455 EP - 464 PB - IEEE ER -