TY - JOUR A1 - Kral, Christian A1 - Haumer, Anton A1 - Haigis, Matthias A1 - Lang, Hermann A1 - Kapeller, Hansjörg T1 - Comparison of a CFD Analysis and a Thermal Equivalent Circuit Model of a TEFC Induction Machine With Measurements JF - IEEE Transactions on Energy Conversion N2 - For a totally enclosed fan-cooled induction machine, two methods of numerical analysis are compared with measurements. The first numerical method is based on computational fluid dynamics (CFDs) and the second one uses a thermal equivalent circuit (TEC). For the analysis based on CFD, a 3-D induction machine including housing is modeled. The numeric solution of the flow equations is determined for stationary temperature distributions. For the TEC, a discretized one-and-a-half-dimensional model of the induction machine is considered. With the TEC model, stationary and transient operating conditions can be simulated. Measurement results are determined by iron-copper-nickel sensors embedded in the stator winding and the housing, as well as by an IR sensor for measuring the rotor temperature. With these measurement signals, stationary and transient operating conditions can be analyzed. For stationary operating conditions, additionally, the housing temperatures are determined by an IR camera. The investigated simulation and measurement methods reveal different local and global temperatures, and thus, only certain aspects and characteristics of the obtained temperatures can be compared. Nevertheless, certain conclusions can be drawn from comparing these aspects considering the actual restrictions of each of the applied methods. KW - asynchronous machines KW - computational fluid dynamics KW - electric sensing devices KW - Fluid flow KW - induction machines KW - numerical analysis KW - simulation KW - temperature Y1 - 2009 U6 - https://doi.org/10.1109/TEC.2009.2025428 SN - 0885-8969 VL - 24 IS - 4 SP - 809 EP - 818 PB - IEEE ER - TY - JOUR A1 - Kral, Christian A1 - Kapeller, Hansjörg A1 - Gragger, Johannes V. A1 - Haumer, Anton A1 - Kubicek, Bernhard T1 - Phenomenon Rotor Fault-Multiple Electrical Rotor Asymmetries in Induction Machines JF - IEEE Transactions on Power Electronics N2 - In the literature, the effects caused by a single or several adjacently broken rotor bars, or a broken end ring are thoroughly investigated. The phenomenon of various nonadjacently broken rotor bars has not been studied so far in detail. Since nonadjacently broken rotor bars may give rise to fault signatures, which are not directly related with the fault extent, it is important to understand the nature of multiple electrical rotor asymmetries in induction machines. The purpose of this paper is thus to investigate several combinations of electrical rotor asymmetries, to systematically elaborate the phenomena related to the broken bars and end rings. In this paper, a sophisticated simulation model and measurement results are used to analyze the phenomenon rotor fault. KW - asynchronous machines KW - Electrical rotor asymmetries KW - induction machine KW - rotor fault KW - Rotors KW - simulation model KW - skewing Y1 - 2010 U6 - https://doi.org/10.1109/TPEL.2009.2037502 SN - 0885-8993 SN - 1941-0107 VL - 25 IS - 5 SP - 1124 EP - 1134 PB - IEEE 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 - 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 - JOUR A1 - Kral, Christian A1 - Haumer, Anton A1 - Kapeller, Hansjörg A1 - Pirker, Franz T1 - Design and Thermal Simulation of Induction Machines for Traction in Electric and Hybrid Electric Vehicles JF - World Electric Vehicle Journal N2 - An electric traction machine for an electric or a hybrid electric vehicle is usually designed for a specific operating point or cycle. For such an operating point or cycle, the masses and the cooling circuit of the electric machine determine the time dependent temperature distribution within the machine. For a specific load cycle, the thermal simulation of the machine can reveal possible mass and size reductions for a given insulation class of the machine. In addition, such simulations allow the comparison of various cooling concepts. In the machine design process, the first step is a conventional electromagnetic machine design. From the geometric data of this design and the material properties, the parameters of a thermal equivalent circuit can be derived. The differential and algebraic equations of the thermal equivalent circuit are solved by a simulation tool to predict the temperatures of the critical parts in the electric machine. A thermal equivalent circuit is accurate enough to predict the thermal behavior of the critical parts in the electric machine, and yet not too complex, to obtain simulation results with moderate numerical effort. This enables an iterative design process to optimize the drive. KW - Induction Motor KW - Electric Drive KW - Modeling KW - Simulation KW - Thermal Management Y1 - 2007 U6 - https://doi.org/10.3390/wevj1010190 SN - 2032-6653 VL - 1 IS - 1 SP - 190 EP - 196 PB - MDPI ER - TY - CHAP A1 - Bäuml, T. A1 - Haumer, Anton A1 - Kapeller, Hansjörg A1 - Starzinger, J. A1 - Farzi, P. T1 - Impact of inverter pulse inhibition on the high-voltage supply system of an electric vehicle — A simulative approach T2 - 2011 IEEE Vehicle Power and Propulsion Conference (VPPC 2011) : Powering sustainable transportation ; Chicago, Illinois, USA, 06. - 09.09.2011 N2 - 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. KW - asynchronous machines KW - Connectors KW - electric vehicles KW - Inverters KW - invertors KW - Mathematical model KW - Object oriented modeling KW - permanent magnet machines KW - power engineering computing KW - Rotors KW - synchronous machines KW - Torque KW - Vehicles Y1 - 2011 SN - 978-1-61284-248-6 SN - 978-1-61284-247-9 SN - 978-1-61284-246-2 U6 - https://doi.org/10.1109/VPPC.2011.6043159 SP - 1 EP - 5 PB - IEEE CY - Piscataway, NJ ER - TY - CHAP A1 - Jungreuthmayer, C. A1 - Bauml, T. A1 - Winter, O. A1 - Ganchev, M. A1 - Kapeller, Hansjörg A1 - Haumer, Anton A1 - Kral, Christian T1 - Heat and fluid flow analysis of an internal permanent magnet synchronous machine by means of computational fluid dynamics T2 - 2011 IEEE International Electric Machines & Drives Conference (IEMDC 2011) ; Niagara Falls, Ontario, Canada, 15 - 18 May 2011 N2 - 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. KW - CFD KW - computational fluid dynamics KW - Cooling KW - finite element analysis KW - interior magnet KW - permanent magnet machines KW - permanent magnet synchronous machine KW - Rotors KW - sensor placement KW - stators KW - synchronous machines KW - temperature KW - temperature distribution KW - thermal analysis Y1 - 2011 SN - 978-1-4577-0060-6 SN - 978-1-4577-0061-3 SN - 978-1-4577-0059-0 U6 - https://doi.org/10.1109/IEMDC.2011.5994651 SP - 515 EP - 520 PB - IEEE CY - Piscataway, NJ ER -