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1

Electromagnetic analysis, efficiency map and thermal analysis of an 80-kW IPM motor with distributed and concentrated winding for electric vehicle applications

Młot Adrian, Korkosz Mariusz, Lechowicz Andrzej, Podhajecki Jerzy, Rawicki Stanisław

Archives of Electrical Engineering

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2022

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Vol. 71, nr 4

981--1002

EN

This paper presents a comparison of an AC radial flux interior permanent magnet (IPM) motor with the distributed winding (DW) and concentrated winding (CW). From time to time, manufacturers of electric vehicles change the design of electric motors, such changes may include changing the DW into CW and vice versa. A change to the winding in a radial permanent magnet synchronous motor may lead to a change in motor parameters during motor operation and /or change in the distribution of the magnetic field and thermal circuit of the electrical machine. The electromagnetic analysis, efficiency map, mechanical stress, and thermal analysis of the machine with the DW and CW are presented in this paper. This article describes the advantages and disadvantages of selected stator winding designs and helps understand manufacturers’ designers how the DW and CW play a key role in achieving the designed motor’s operational parameters such as continuous performance. Analyzing the performance of both machines will help identify their advantages and disadvantages with regard to thermal phenomena, magnetic field and operational parameters of the presented IPM prototypes. Both prototypes are based on commonly used topologies such as 12/8 (slot/pole) and 30/8 (slot/pole) IPM motors consisting of magnets arranged in a V-shape. The AC IPM motor was designed for an 80 kW propulsion system to achieve 170 N·m at a base speed of 4 500 rpm. Modern CAD tools are utilized throughout the numerical computations based on 2-D finite element methods. Selected test data are used to verify and validate the accuracy of finite element models.

2

Design of a race-track coil for measurements of AC power losses in high-temperature superconducting tapes

Trojanowski S., Ciszek M., Maievskyi E.

Metrology and Measurement Systems

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2014

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Vol. 21, nr 2

293--304

EN

One of the most important parameters, crucial to applications of superconductors in cryo-electrotechnique, is power loss. Measurements of losses in superconducting long sample wires require AC magnetic fields of a special geometry and appropriate high homogeneity. In the paper part of the theoretical basis for calculations and a simple design method for a race-track coil set are presented. An example of such home-made coils, with a magnetic field uniformity of about 0.2 % over the range of about 8 cm, is given. Also a simple electronic measurement system for the determination of AC magnetization loss in samples of superconducting tapes is presented.

3

Wpływ efektu zbliżeniowego i naskórkowości na straty mocy w tworniku

Młot A., Korkosz M., Grodzki P., Łukaniszyn M.

Przegląd Elektrotechniczny

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2013

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R. 89, nr 12

44-48

PL

W artykule przedstawiono analizę strat mocy w żelazie i miedzi przy zasileniu uzwojenia sygnałem sinusoidalnym o wysokich częstotliwościach. Straty mocy wyznaczone z modelu matematycznego silnika zweryfikowano z pomiarami jakie wykonano na zbudowanym prototypie rdzenia stojana silnika komutatorowego z nawiniętym uzwojeniem. W badaniach uwzględniono wpływ efektu naskórkowości oraz efektu zbliżeniowego na straty mocy w miedzi. Głównym zagadnieniem w pracy było zbadanie wpływu pola magnetycznego połączeń czołowych uzwojeń na straty mocy, poprzez porównanie obliczeń na modelach dwuwymiarowych (2D) i trójwymiarowych (3D) opartych na metodzie elementów skończonych (MES).

EN

Accurate prediction of power loss distribution within an electrical device is highly desirable as it allows for thermal behavior to be evaluated at the early design stage. This paper focuses on the ac copper loss caused by circulating current effects in electrical machines. Two different phenomena lead to additional ac losses: skin effect and proximity effect. Skin effect is the tendency for high frequency currents to flow on the surface of a conductor and can be mitigated through the use of small conductor strands. The proximity effect is the tendency for current to flow in other undesirable patterns that form localized current loops or concentrated distribution due to the presence of a magnetic field generated by nearby conductors. To evaluate the ac copper loss within the analyzed machine a simplified approach is adopted utilizing the segmented stator topology. To minimize and show an effect of proximity and/or end-winding on the ac copper loss at presented electrical machine a number of winding arrangement are investigated. Three-dimensional and two-dimensional finite element analysis was applied to calculate a ratio of ac to dc resistant at high frequency sinusoidal current. This resistant ratio demonstrates the amount of copper loss which is increased by high frequency. The resistant ratio is strongly dependent on frequency, temperature and shape of slot and size of slot opening. The theoretical finding is compared against the experimental data of total power losses.

4

FEM-based development of measurement system for magnetic fluid characterization

Bekovič M., Hamler A.

Przegląd Elektrotechniczny

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2011

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R. 87, nr 3

9-12

EN

In this article we describe the FEM based development of measurement system for determination of magnetic fluid heating effect when exposed to ac magnetic field. In the design phase several different geometries of excitation coils has been tested with the aim of achieving the homogeneity of the magnetic field, using FEM magnetic analysis. Furthermore thermal FEM analysis has be en performed with intention of selecting suitable materials in the measuring system to achieve thermal stability.

PL

W artykule opisany jest system pomiarowy bazujący na metodzie elementów skończonych (FEM) dla określenia efektu cieplnego w płynie magnetycznym wystawionym na pole magnetyczne AC. W fazie projektowej kilkanaście geometrii cewek wzbudzających zostało przetestowanych przy użyciu metody elementów skończonych w celu osiągnięcia jednorodności pola magnetycznego. Ponadto, analiza cieplna za pomocą FEM została przeprowadzona dla wyselekcjonowania materiałów pozwalających na osiągnięcie cieplnej stabilności

5

Influence of magnetic materials on transport properties of applied superconductors

Głowacki B., Majoros M., Campbell A.

Przegląd Elektrotechniczny

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2009

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R. 85, nr 5

151-154

EN

Magnetic materials can help to improve the performance of practical superconductors on the macro/micro scale as magnetic diverters and also on the nanoscale as effective pinning centres. It was established by numerical modelling that magnetic shielding of the superconducting filaments reduces AC losses in self-field conditions due to decoupling of the filaments and, at the same time, it increases the critical current of the superconducting composite.

PL

Magnetyczne materiały umożlowiają polepszene wlasności naprzewodzących nadprzewodników technicznych w skali makro jako magnetyczne osłony, jak również w skali nano jako efektywne centra zaczepiania strumienia magnetycznego. Udowodniono przy użyciu modelowania numerycznego, że magnetyczne ekranowanie włókien nadprzewodnikowych redukuje straty przemiennoprądowe w wyniku magnetycznego rozłączenia włókien, jak rownież powoduje wzrost prądu krytycznego przewodu.