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  • 1.
    Anpalahan, Peethamparam
    et al.
    KTH, Skolan för elektro- och systemteknik (EES), Elektrisk energiomvandling.
    Soulard, Juliette
    KTH, Skolan för elektro- och systemteknik (EES), Elektrisk energiomvandling.
    Nee, Hans-Peter
    KTH, Skolan för elektro- och systemteknik (EES), Elektrisk energiomvandling.
    Design Steps towards a High Power Factor Transverse Flux Machine2001Inngår i: Proc. of the European Conference on Power Electronics and Applications (EPE), Graz, Austria, August 2001 / [ed] EPE, 2001Konferansepaper (Fagfellevurdert)
    Abstract [en]

    This article describes a topology of three-phase transverse flux machine and the derivation of ananalytical model which does not exist in the literature. Three dimensional finite element analysis isalso used to get more accurate results. Steps carried out to obtain a better power factor are presented.

  • 2.
    Antonopoulos, Antonios
    et al.
    KTH, Skolan för elektro- och systemteknik (EES), Elektrisk energiomvandling.
    Mörée, Gustav
    KTH, Skolan för elektro- och systemteknik (EES), Elektrisk energiomvandling.
    Soulard, Juliette
    KTH, Skolan för elektro- och systemteknik (EES), Elektrisk energiomvandling.
    Ängquist, Lennart
    KTH, Skolan för elektro- och systemteknik (EES), Elektrisk energiomvandling.
    Nee, Hans-Peter
    KTH, Skolan för elektro- och systemteknik (EES), Elektrisk energiomvandling.
    Experimental evaluation of the impact of harmonics on induction motors fed by modular multilevel converters2014Inngår i: Proceedings - 2014 International Conference on Electrical Machines, ICEM 2014, 2014, s. 768-775Konferansepaper (Fagfellevurdert)
    Abstract [en]

    Inverter-based electrical-machine drives suffer from significantly higher losses compared to sinusoidal-supply-based alternatives, fed directly from the grid. Using multilevel inverters it becomes possible to partially mitigate the effects of the switched supply waveform, while keeping the advantages of variable-speed operation. This paper aims to evaluate the increase of the losses occurring in an induction motor (IM) fed by a modular multilevel converter (M2C), when compared to grid-connected operation, in order to evaluate the impact of the inverter-generated harmonics in the machine. It is confirmed that the losses created in the motor due to the harmonic content of the inverter-generated waveforms are very low, and almost equivalent to a purely sinusoidal supply. The investigation includes an analysis of the harmonic content from experimental waveforms obtained by an 11-kW IM laboratory setup, and it is further supported by measurements of the temperature rise in the IM-stator windings. It is concluded that the M2C could create the conditions even for high-power motors to be operated without any derating.

  • 3. Arshad, W.
    et al.
    Soulard, Juliette
    KTH, Skolan för elektro- och systemteknik (EES), Elektrisk energiomvandling.
    Eriksson, Bengt
    Malmros, Bo
    Incorporating lamination processing and component manufacturing in electrical machine design tools2007Inngår i: Conference Record: IAS Annual Meeting, 2007, s. 94-102Konferansepaper (Fagfellevurdert)
    Abstract [en]

    Measures to improve the modeling of steel-sheet laminations in electrical machine design tools are studied. Only the magnetic properties, namely, the permeability (BH curves) and the iron losses are addressed. The sensitivity of these properties upon dimensional, directional (anisotropy) and excitation variations, as well as upon the electrical machines manufacturing steps is evaluated. The studied electrical machines manufacturing step are: guillotine, laser-cutting, welding, pressing and punching. The properties of the delivered lamination coils and the various associated loss figures are also statistically benchmarked. The focus is on finding guidelines for incorporation of these sensitivities in design tools when needed. For this purpose, 5 Hz to 10 kHz tests are conducted on Epstein strips, on L-shaped segments and on standard stator laminations. Two different steel grades are studied. It is shown that the lateral dimension, anisotropy and welding influences are much more pronounced then those for punching, pressing and laser cutting and hence, need to be addressed in design tools. It is found that the commonly used Epstein test results of the coils are slightly inferior to the mean loss value of the online-testing (losses that are measured at every 1 m of the entire coil length). It is also noted that, the delivered laminations are almost always better than those ordered and the losses for each individual lamination coil are nearly constant.

  • 4.
    Arshad, Waqas
    et al.
    KTH, Skolan för elektro- och systemteknik (EES), Elektriska maskiner och effektelektronik (stängd 20110930).
    Chin, Yung-kang Robert
    KTH, Skolan för elektro- och systemteknik (EES), Elektriska maskiner och effektelektronik (stängd 20110930).
    Bäckström, Thomas
    KTH, Skolan för elektro- och systemteknik (EES), Elektriska maskiner och effektelektronik (stängd 20110930).
    Soulard, Juliette
    KTH, Skolan för elektro- och systemteknik (EES), Elektriska maskiner och effektelektronik (stängd 20110930).
    Östlund, Stefan
    KTH, Skolan för elektro- och systemteknik (EES), Elektriska maskiner och effektelektronik (stängd 20110930).
    Sadarangani, Chandur
    KTH, Skolan för elektro- och systemteknik (EES), Elektriska maskiner och effektelektronik (stängd 20110930).
    On finding compact motor solutions for transient applications2001Inngår i: Proceedings of the IEEE International Electric Machines Conference, 2001, s. 743-747Konferansepaper (Fagfellevurdert)
  • 5.
    Berglund, Anders
    et al.
    KTH, Skolan för industriell teknik och management (ITM), Maskinkonstruktion (Inst.), Integrerad produktutveckling. KTH.
    Havtun, Hans
    KTH, Skolan för industriell teknik och management (ITM), Energiteknik. KTH.
    Jerbrant, Anna
    KTH, Skolan för industriell teknik och management (ITM), Industriell ekonomi och organisation (Inst.), Industriell Management. KTH.
    Wingård, Lasse
    KTH, Skolan för industriell teknik och management (ITM), Industriell produktion. KTH.
    Andersson, Magnus
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Material- och nanofysik.
    Hedin, Björn
    KTH, Skolan för datavetenskap och kommunikation (CSC), Medieteknik och interaktionsdesign, MID.
    Soulard, Juliette
    KTH, Skolan för elektro- och systemteknik (EES).
    Kjellgren, Björn
    KTH, Skolan för teknikvetenskaplig kommunikation och lärande (ECE), Lärande, Språk och kommunikation.
    The pedagogical developers initiative - development, implementation and lessons learned from a systematic approach to faculty development2016Inngår i: Proceedings of the 12th International CDIO Conference, Turku University of Applied Sciences, Turku, Finland, June 12-16, 2016, Turku University , 2016, s. 497-508Konferansepaper (Fagfellevurdert)
    Abstract [en]

    This paper presents a systematic, university--wide approach to creating an encompassing movement towards faculty development. In 2014, KTH Royal Institute of Technology launched the pedagogical developers initiative, appointing part--time pedagogical developers among teachers from all schools of KTH, to implement and strengthen good teaching and learning practices among faculty and students. They are teachers active in different educational programmes, with experience of, and interest in, pedagogical issues. In line with CDIO standard 10, the purpose of the pedagogical developers’ initiative is to facilitate cooperation and knowledge exchange between faculty members, and to establish communities of practice. The paper presents the activities, processes for developing these activities and preliminary results from the initiative’s second year, which focused much on supporting faculty development by putting into place a series of workshops, a format chosen for its combination of active community-building learning and time efficiency. The topics of the workshops emerged to meet faculty needs identified by the pedagogical developers during the first year. The workshops were created by smaller teams of pedagogical developers from different schools of KTH. This enabled a wide array of experiences and perspectives to be incorporated into the workshops. Main focuses of the workshops have been on creating internal discussions in dynamic communities of practice on specific subjects of interest, and on creating forums for exchange of ideas, open to the whole faculty. During Autumn 2015, the workshops have been offered as voluntary add-on parts of the basic course in teaching and learning offered to faculty at KTH. This first round of workshops generated a positive interest from teachers, and participant feedback indicates that they particularly appreciated the opportunity to work directly with their own courses and the opportunity to discuss pedagogical aspects with peers. 

  • 6.
    Berglund, Anders
    et al.
    KTH, Skolan för industriell teknik och management (ITM), Maskinkonstruktion (Inst.), Integrerad produktutveckling.
    Havtun, Hans
    KTH, Skolan för industriell teknik och management (ITM), Energiteknik, Tillämpad termodynamik och kylteknik.
    Johansson, Hans Bengt
    KTH, Skolan för industriell teknik och management (ITM), Maskinkonstruktion (Inst.), Mekatronik.
    Jerbrant, Anna
    KTH, Skolan för industriell teknik och management (ITM), Industriell ekonomi och organisation (Inst.), Industriell Management.
    Andersson, Magnus
    KTH, Skolan för informations- och kommunikationsteknik (ICT).
    Hedin, Björn
    KTH, Skolan för datavetenskap och kommunikation (CSC), Medieteknik och interaktionsdesign, MID.
    Soulard, Juliette
    KTH, Skolan för elektro- och systemteknik (EES), Elektrisk energiomvandling.
    Kjellgren, Björn
    KTH, Skolan för teknikvetenskaplig kommunikation och lärande (ECE).
    The Pedagogical Developers Initiative – Changing Educational Practices and Strengthening CDIO skills2015Inngår i: Proceedings of the 11th International CDIO Conference, Chengdu, China, June 8-11 2015, 2015Konferansepaper (Fagfellevurdert)
    Abstract [en]

    This paper put emphasis on change agents within the universities and how local initiatives can be systematically approached and ramped up. Rooted in the challenges and constraints that have been addressed in past educational program initiatives, the case consists of specific focus areas to leverage impact. Universities continuously strives to provide the best conditions for an inspiring and prosperous learning environment, and to provide educational programs with teaching of excellent educational quality. KTH is no exception and therefore the university management has initiated a pedagogical program starting in 2014. One of the first thing initiated within the framework of this pedagogical program is the creation of a group of 24 pedagogical developers.

    The focus for the pedagogical developers is to facilitate the opportunities for KTHs faculty to work together and create consensus on educational development in different teaching teams. This paper presents the University's pedagogical developers' initiative as a whole and how this has been outlined in detail to reach specific redesign targets. The School of Industrial Engineering and Management pedagogical group consists of five practicing teachers that besides this new role also engage heavily in various courses of the School's departments. Since the pedagogical initiative is aligned with several important CDIO aspects, e.g. the learning environment, formats of formative feedback, assessment and examination there is also importance to reassure this in the existing Master level programs.

    At KTH the five-year comprehensive Master of Science in Engineering programs concern distinct vocational educations in which the CDIO aspects are very important. At the same time the programs has been divided in a basic level (B.Sc. in Engineering) of three years and a advanced level (M.Sc.) of two years. This has for instance made it harder to align the progression between first cycle level and second cycle level regarding for instance the CDIO efforts (e.g. oral and written communication, teamwork). This paper will therefore discuss and enhance how the pedagogical programme, we as pedagogical developers, can support and strengthen the initiation and implementation of the CDIO aspects in the education.

  • 7. Bourchas, K.
    et al.
    Stening, A.
    Soulard, Juliette
    KTH, Skolan för elektro- och systemteknik (EES).
    Broddefalk, A.
    Lindenmo, M.
    Dahlén, M.
    Gyllensten, F.
    Influence of Cutting and Welding on Magnetic Properties of Electrical Steels2016Inngår i: Proceedings - 2016 22nd International Conference on Electrical Machines, ICEM 2016, Institute of Electrical and Electronics Engineers (IEEE), 2016, s. 1815-1821, artikkel-id 7732770Konferansepaper (Fagfellevurdert)
    Abstract [en]

    The magnetic properties, namely the iron losses and the relative permeability, of SiFe electrical steel laminations after mechanical and laser cutting are studied. Mechanical cutting with guillotine shears and cutting by means of fiber and CO2 lasers are considered. The magnetic measurements are conducted on the Epstein frame for frequencies of 50, 100 and 200 Hz. The specimens also include Epstein strips with 1, 2 and 3 additional cutting edges along their length, in order to increase the cutting effect and the characterization data. Mechanical cutting results in more than 20% iron loss increase and more than 40% relative permeability reduction at 1 T for 0.5 mm gauge, for a strip width of 10 mm compared with the reference of 30 mm, while corresponding values for laser cutting are 40% and 60%. It is also noted that different steel grades of the same raw material show lower magnetic deterioration with thinner lamination thickness. The influence of welding is also investigated by means of Epstein measurements. Experiments show an iron loss increase of up to 50% with a corresponding 62% reduction in the permeability compared to similar non-welded laminations. A model that incorporates the cutting effect with geometry dependency is developed and implemented in a FEM-based motor design software. Simulations made for an industrial low voltage induction motor indicate a more than 15% increase in the iron losses compared to a model that does not consider the mechanical cutting effect. In the case of laser cutting, this increase reaches 30% to 50%, depending on laser settings.

  • 8. Carlsson, Fredrik
    et al.
    Soulard, Juliette
    KTH, Skolan för elektro- och systemteknik (EES), Elektrisk energiomvandling.
    Grop, Henrik
    KTH, Skolan för elektro- och systemteknik (EES), Elektrisk energiomvandling.
    Free Fall Attraction as a Practical and Theoretical Project in the Electrical Engineering Education2006Konferansepaper (Fagfellevurdert)
    Abstract [en]

    In the first year of the studies in the five-yearMaster of Science programme in Electrical Engineering at KTH,there is a course named “Electro project”. The students that takethis compulsory course choose between several projects and thispaper describes a newly invented project called Free Fall, whichpractically and theoretically demonstrates in a simple andinteresting way important electrical engineering equations forthe students. The students study, calculate and build a gondolathat first accelerates when it falls freely along a tower from itstop and then decelerate with eddy current brakes. The studentslearn apart from modelling of physical phenomena, mechanicalconstruction, validation, measurements and collaboration withinthe group as well as with the laboratory staff.

  • 9.
    Chin, Yung-Kang Robert
    et al.
    KTH, Tidigare Institutioner                               , Elektrotekniska system.
    Soulard, Juliette
    KTH, Tidigare Institutioner                               , Elektrotekniska system.
    A theoretical study on permanent magnet synchronous motors for electric vehicles2003Inngår i: IPEC 2003: PROCEEDINGS OF THE 6TH INTERNATIONAL POWER ENGINEERING CONFERENCE, SINGAPORE: NANYANG TECHNOLOGICAL UNIV , 2003, s. 435-440Konferansepaper (Fagfellevurdert)
    Abstract [en]

    This paper addresses the theoretical design of a conventional radial flux permanent magnet synchronous motor (PMSM) with field-weakening capability for electric vehicles. The study applies to both surface mounted and inset magnet rotor configurations. Various losses estimations are embedded into the design procedures to ensure that the desired overall drive performance is achieved. Influences of parameters such as air gap size and magnet thickness on the performances are studied. Back EMF and cogging torque are also investigated and analysed by using both the Finite Element Method (FEM) and an analytical approach. Design examples of various PMSMs with a given stator geometry are presented.

  • 10.
    Chin, Yung-Kang Robert
    et al.
    KTH, Skolan för elektro- och systemteknik (EES), Elektriska maskiner och effektelektronik.
    Soulard, Juliette
    KTH, Skolan för elektro- och systemteknik (EES), Elektriska maskiner och effektelektronik.
    Design study of a traction motor for electric vehicles2005Inngår i: ICEMS 2005: Proceedings of the Eighth International Conference on Electrical Machines and Systems, 2005, Vol. 1, s. 786-791Konferansepaper (Fagfellevurdert)
    Abstract [en]

    This paper presents the design study of a traction motor used in electric vehicles. The design is a permanent magnet synchronous motor (PMSM) type with an inset permanent rotor configuration. With the given constant power speed range (CPSR), a design methodology is developed to reach the required specifications.

  • 11.
    Chin, Yung-Kang Robert
    et al.
    KTH, Tidigare Institutioner                               , Elektrotekniska system.
    Soulard, Juliette
    KTH, Tidigare Institutioner                               , Elektrotekniska system.
    Modeling of iron losses in permanent magnet synchronous motors with field-weakening capability for electric vehicles2003Inngår i: International Journal of Automotive Technology, ISSN 1229-9138, E-ISSN 1976-3832, Vol. 4, nr 2, s. 87-94Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Recent advancements of permanent magnet (PM) materials and solid-state devices have contributed to a substantial performance improvement of permanent magnet machines. Owing to the rare-earth PMs, these motors have higher efficiency, power factor, output power per mass and volume, and better dynamic performance than induction motors without sacrificing reliability. Not surprisingly, they are continuously receiving serious considerations for a variety of automotive and propulsion applications. An electric vehicle (EV) requires a high-efficient propulsion system having a wide operating range and A capability of generating a high peak torque for short durations. ne improvement of torque-speed performance for these systems is consequently very important, and researches in various aspects are therefore being actively pursued. A great emphasis has been placed on the efficiency and optimal utilization of PM machines. This requires attention to many aspects related to the machine design and overall performance. In this respect, the prediction of iron losses is particularly indispensable and challenging, especially for drives with a deep field-weakening range. The objective of this paper is to present iron loss estimations of a PM motor over a wide speed range. As aforementioned, in EV applications core losses can be significant during high-speed operation and it is imperative to evaluate these losses accurately and take them into consideration during the motor design stage. In this investigation, the losses are predicted by using an analytical model and a 2D time-stepped finite element method (FEM). The results from different analytical approaches are compared with the FEM computations. The validity of each model is then evaluated by these comparisons.

  • 12. Cossale, M.
    et al.
    Krings, Andreas
    KTH, Skolan för elektro- och systemteknik (EES), Elektrisk energiomvandling.
    Soulard, Juliette
    KTH, Skolan för elektro- och systemteknik (EES), Elektrisk energiomvandling.
    Boglietti, A.
    Cavagnino, A.
    Practical investigations on cobalt-iron laminations for electrical machines2014Inngår i: Proceedings - 2014 International Conference on Electrical Machines, ICEM 2014, 2014, s. 1390-1395Konferansepaper (Fagfellevurdert)
    Abstract [en]

    The adoption of high performance soft magnetic material can be considered a possible way to respect the challenging design specifications for aerospace and automotive electrical machines. This paper presents an accurate, non-invasive investigation of magnetic and energetic properties of cobalt-iron stator cores. In particular, the focus lies on the annealing processes aimed to maximize the magnetic saturation and the mechanical strength. Three cobalt-iron stator core samples coming from different annealing processes have been analyzed. Stator slot effects on the magnetic measurements have been investigated by Finite Element Method. A fringing effect correction factor to be applied on the measurements is reported too. In addition, micrographic analysis of the material structure is presented as well as the iron losses separation coefficients.

  • 13.
    Cossale, Marco
    et al.
    Dipartimento Energia, Politecnico di Torino, Italy .
    Krings, Andreas
    ABB Corporate Research, Sweden .
    Soulard, Juliette
    KTH, Skolan för elektro- och systemteknik (EES).
    Boglietti, Aldo
    Dipartimento Energia, Politecnico di Torino, Italy .
    Cavagnino, Andrea
    Dipartimento Energia, Politecnico di Torino, Italy .
    Practical Investigations on Cobalt–Iron Laminations for Electrical Machines2015Inngår i: IEEE transactions on industry applications, ISSN 0093-9994, E-ISSN 1939-9367, Vol. 51, nr 4, s. 2933-2939Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The adoption of high-performance soft magnetic material can be considered a possible way to respect the challenging design specifications for aerospace and automotive electrical machines. This paper presents an accurate noninvasive investigation of magnetic and energetic properties of cobalt–iron stator cores. In particular, the focus lies on the annealing processes aimed to maximize the magnetic saturation and the mechanical strength. Three cobalt–iron stator core samples coming from different annealing processes have been analyzed, both from the BH characteristics and losses viewpoints. Stator slot effects on the magnetic measurements have been investigated by finite-element method. A fringing effect correction factor to be applied on the measured BH curves is as well reported. In order to complete the experimental campaign analysis, micrographic analysis of the material structure is presented, as well as the iron losses separation coefficients.

  • 14.
    Dmitry, Svechkarenko
    et al.
    KTH, Skolan för elektro- och systemteknik (EES), Elektriska maskiner och effektelektronik (stängd 20110930).
    Soulard, Juliette
    KTH, Skolan för elektro- och systemteknik (EES), Elektriska maskiner och effektelektronik (stängd 20110930).
    Sadarangani, Chandur
    KTH, Skolan för elektro- och systemteknik (EES), Elektriska maskiner och effektelektronik (stängd 20110930).
    A Novel Transverse Flux Generator in Direct-Driven Wind Turbines2006Konferansepaper (Fagfellevurdert)
    Abstract [en]

    The higher specific torque and power density of atransverse flux permanent magnet (TFPM) machine in comparisonto a conventional machine makes it a promising direct-drivenwind turbine generator. The new topology presented in this paperis believed to have a better utilization of the available in thenacelle space. This would favor a reduced inactive weight of thegenerator and thus remove one of the major obstacles for largewind power units. The new topology is presented together withthe analytical model used in the design procedure. The analyticalmodel is used in a parametric study and the first conclusionsabout the performance of the new TFPM topology are drawn.

  • 15.
    Dmitry, Svechkarenko
    et al.
    KTH, Skolan för elektro- och systemteknik (EES), Elektriska maskiner och effektelektronik (stängd 20110930).
    Soulard, Juliette
    KTH, Skolan för elektro- och systemteknik (EES), Elektriska maskiner och effektelektronik (stängd 20110930).
    Sadarangani, Chandur
    KTH, Skolan för elektro- och systemteknik (EES), Elektriska maskiner och effektelektronik (stängd 20110930).
    Analysis of a Novel Transverse Flux Generator in Direct-driven Wind Turbines2006Konferansepaper (Fagfellevurdert)
    Abstract [en]

    This paper presents analysis of a novel transverseflux direct-driven wind generator. The analytical model for thecalculation of different parts of the inductance is developed andapplied for the evaluation of machine performance with respectto its geometry. Generators rated for 3, 5, 7, and 10 MW outputpower are investigated. The possible ranges of design parametersare discussed and conclusions are drawn.

  • 16. Gonzalez, A. Garcia
    et al.
    Millinger, Jonas
    KTH, Skolan för elektro- och systemteknik (EES), Elkraftteknik.
    Soulard, Juliette
    KTH, Skolan för elektro- och systemteknik (EES).
    Magnet Losses in Inverter-Fed Two-Pole PM Machines2016Inngår i: Proceedings - 2016 22nd International Conference on Electrical Machines, ICEM 2016, Institute of Electrical and Electronics Engineers (IEEE), 2016, s. 1854-1860, artikkel-id 7732776Konferansepaper (Fagfellevurdert)
    Abstract [en]

    This article deals with the estimation of magnet losses in a permanent-magnet motor inserted in a nut-runner. This type of machine has interesting features such as being two-pole, slot-less and running at a high speed (30000 rpm). Two analytical models were chosen from the literature. A numerical estimation of the losses with 2D Finite Element Method was carried out. A detailed investigation of the effect of simulation settings (e.g., mesh size, time-step, remanence flux density in the magnet, superposition of the losses, etc.) was performed. Finally, calculation of losses with 3D-FEM were also run in order to compare the calculated losses with both analytical and 2D-FEM results. The estimation of the losses focuses on a range of frequencies between 10 and 100 kHz.

  • 17.
    Grop, Henrik
    et al.
    KTH, Skolan för elektro- och systemteknik (EES), Elektrisk energiomvandling.
    Soulard, Juliette
    KTH, Skolan för elektro- och systemteknik (EES), Elektrisk energiomvandling.
    Krings, Andreas
    KTH, Skolan för elektro- och systemteknik (EES), Elektrisk energiomvandling.
    Persson, Holger
    Semi-analytical modeling of the end-winding self-inductance in large AC machines2012Inngår i: Proceedings of the 15th International Conference on Electrical Machines and Systems (ICEMS), Institution of Electrical Engineers of Japan (IEEJ), 2012, s. 6401782-Konferansepaper (Fagfellevurdert)
    Abstract [en]

    A semi-analytical model for calculation of self-inductance of complex coil geometries having a rectangular cross-section (form-wound coils) is proposed and evaluated. A step-by-step validation is carried on using both 2D-FEM simulations and measurements on a coil placed in air. A second version of the model is developed, to speed up the computation time through removing the possibility to analyze the contribution of the internal flux in the conductor. The predicted value of the self-inductance of a diamond-shaped coil placed in air is within 5% of the measured value.

  • 18.
    Grop, Henrik
    et al.
    KTH, Skolan för elektro- och systemteknik (EES), Elektriska maskiner och effektelektronik.
    Soulard, Juliette
    KTH, Skolan för elektro- och systemteknik (EES), Elektriska maskiner och effektelektronik.
    Persson, H.
    Stator Slot Leakage in AC-Machines Equipped With Fractional Conductor Windings2009Inngår i: 2009 INTERNATIONAL CONFERENCE ON ELECTRICAL MACHINES AND SYSTEMS, 2009, s. 168-173Konferansepaper (Fagfellevurdert)
    Abstract [en]

    This paper presents a slot leakage model for stator windings having a fractional number of turns per slot. The results are compared with finite element simulations and measurements using search coils in a prototype machine. Although the slot leakage model predicts the leakage correctly in the slot bottom, the model cannot be used on its own for the slot top since the zig-zag leakage was very pronounced just below the slot wedge.

  • 19.
    Grop, Henrik
    et al.
    KTH, Skolan för elektro- och systemteknik (EES), Elektriska maskiner och effektelektronik (stängd 20110930).
    Soulard, Juliette
    KTH, Skolan för elektro- och systemteknik (EES), Elektriska maskiner och effektelektronik (stängd 20110930).
    Persson, Holger
    Theoretical Investigation of Fractional Conductor Windings for AC-Machines: Definition, Air-gap m.m.f. and Winding Factors2008Inngår i: ICEM: 2008 International Conference on Electrical Machines, NEW YORK: IEEE , 2008, s. 529-534Konferansepaper (Fagfellevurdert)
    Abstract [en]

    This paper introduces the concept of fractional conductor windings for AC-machines. They allow to obtain fractional equivalent number of conductors per slot. Different arrangements of windings are presented. The harmonic spectrum of the armature magneto-motive force in the air-gap is then analyzed in order to derive rules for choosing suitable combinations using winding factors.

  • 20.
    Grop, Henrik
    et al.
    KTH, Skolan för elektro- och systemteknik (EES), Elektrisk energiomvandling.
    Soulard, Juliette
    KTH, Skolan för elektro- och systemteknik (EES), Elektrisk energiomvandling.
    Persson, Holger
    Savinovic, Gjordje
    Bergman, Leif
    End-Winding Inductances for Synchronous Machines in the MVA-Range with Fractional Conductor Windings2011Inngår i: Proceeding of Portuguese-Spanish Conference on Electrical Engineering, 2011Konferansepaper (Annet vitenskapelig)
  • 21.
    Krings, Andreas
    et al.
    KTH, Skolan för elektro- och systemteknik (EES), Elektrisk energiomvandling.
    Cossale, Marco
    Soulard, Juliette
    KTH, Skolan för elektro- och systemteknik (EES), Elektrisk energiomvandling.
    Boglietti, Aldo
    Cavagnino, Andrea
    Manufacturing influence on the magnetic properties and iron losses in cobalt-iron stator cores for electrical machines2014Inngår i: Proceedings - Energy Conversion Congress and Exposition (ECCE), 2014 IEEE / [ed] IEEE Conference Publications, 2014, s. 5595-5601Konferansepaper (Fagfellevurdert)
    Abstract [en]

    The manufacturing influence on the magnetic properties and iron losses in stator cores made of cobalt-iron is investigated in this study, with a focus on the annealing and stacking process. Hysteresis and iron loss curves from measurements as well as a microscopic structure analysis are presented. FEM simulations are used to investigate the fringing effect in the stator cores due to the stator slots and others geometrical effects. A correction factor is derived and applied to the measurements. Furthermore, it is shown, that for cobalt-iron lamination sheets, the annealing process with an exact temperature and duration is absolutely essential to achieve expected magnetic and mechanical properties in the material.

  • 22.
    Krings, Andreas
    et al.
    KTH, Skolan för elektro- och systemteknik (EES), Elektrisk energiomvandling.
    Cossale, Marco
    Politecnico di Torino.
    Tenconi, Alberto
    Politecnico di Torino.
    Soulard, Juliette
    KTH, Skolan för elektro- och systemteknik (EES), Elektrisk energiomvandling.
    Magnetic Materials for Electrical Machines: a Selection Guide from the Engineering Application Point of View2014Konferansepaper (Fagfellevurdert)
  • 23.
    Krings, Andreas
    et al.
    KTH, Skolan för elektro- och systemteknik (EES), Elektrisk energiomvandling. ABB Corporate Research, Sweden.
    Cossale, Marco
    Dipartimento Energia, Politecnico di Torino, Italy.
    Tenconi, Alberto
    Dipartimento Energia, Politecnico di Torino, Italy.
    Soulard, Juliette
    KTH, Skolan för elektro- och systemteknik (EES), Elektrisk energiomvandling.
    Cavagnino, Andrea
    Dipartimento Energia, Politecnico di Torino, Italy.
    Boglietti, Aldo
    Dipartimento Energia, Politecnico di Torino, Italy.
    Characteristics comparison and selection guide for magnetic materials used in electrical machines2015Inngår i: 2015 IEEE International Electric Machines Drives Conference (IEMDC), IEEE , 2015, s. 1152-1157Konferansepaper (Fagfellevurdert)
    Abstract [en]

    This paper presents an up-to-date magnetic materialinvestigation and overview on magnetic materials used in rotatingelectrical machines. The focus is on small to medium-sizedhigh-performance and high-efficiency permanent-magnet andinduction motors for different application scenarios. The inves-tigated materials include silicon-iron, nickel-iron, and cobalt-iron lamination steels, as well as soft magnetic composites andamorphous magnetic materials. The technical focus is on themagnetic properties and iron losses as well as the manufacturinginfluence and required thermal treatments during the manufac-turing process. A new loss to flux density factor is introducedto compare theBHmagnetization curve and the iron losses ofdifferent materials in the same diagram. The aim of the paper isto give the machine designer an efficient material overview andselection guide during the early machine design process.

  • 24.
    Krings, Andreas
    et al.
    KTH, Skolan för elektro- och systemteknik (EES), Elektrisk energiomvandling.
    Mousavi, Seyedali
    KTH, Skolan för elektro- och systemteknik (EES), Elektroteknisk teori och konstruktion.
    Wallmark, Oskar
    KTH, Skolan för elektro- och systemteknik (EES), Elektrisk energiomvandling.
    Soulard, Juliette
    KTH, Skolan för elektro- och systemteknik (EES), Elektrisk energiomvandling.
    Temperature Influence of NiFe Steel Laminations on the Characteristics of Small Slotless Permanent Magnet Machines2013Inngår i: IEEE transactions on magnetics, ISSN 0018-9464, E-ISSN 1941-0069, Vol. 49, nr 7, s. 4064-4067Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    High performance electrical machines can operate at temperatures of 100 degrees C and beyond in rotor and stator cores. However, magnetic properties are generally measured at room temperatures around 23 degrees C to 25 degrees C according to the standards, even if it is known that the magnetization of some materials is substantially influenced by increasing temperatures. This paper investigates the thermal influence on the magnetic properties and iron losses in the stator cores of small slotless permanent magnet synchronous machines (PMSMs). The stator stack is made of thin nickel iron (NiFe) lamination sheets. Magnetic measurements of the stator core are conducted for different frequencies and flux densities at several temperatures between 25 degrees C and 105 degrees C. The obtained measurement data is afterwards used in finite element method (FEM) simulations to investigate the influence of the magnetic property change on the machine performance. For the PMSM in consideration, the FEM simulations show that an increased stator core temperature reduces the electromagnetic torque considerably; approximately 1/3 of the torque reduction due to increased rotor magnet and stator core temperatures (from 25 degrees C to 100 degrees C) can be attributed to the increased stator core temperature.

  • 25.
    Krings, Andreas
    et al.
    KTH, Skolan för elektro- och systemteknik (EES), Elektrisk energiomvandling.
    Nategh, Shafigh
    KTH, Skolan för elektro- och systemteknik (EES), Elektrisk energiomvandling.
    Stening, Alexander
    KTH, Skolan för elektro- och systemteknik (EES), Elektrisk energiomvandling.
    Grop, Henrik
    KTH, Skolan för elektro- och systemteknik (EES), Elektrisk energiomvandling.
    Wallmark, Oskar
    KTH, Skolan för elektro- och systemteknik (EES), Elektrisk energiomvandling.
    Soulard, Juliette
    KTH, Skolan för elektro- och systemteknik (EES), Elektrisk energiomvandling.
    Measurement and Modeling of Iron Losses in Electrical Machines (Invited Paper)2012Inngår i: Proceedings of the 5th International Conference Magnetism and Metallurgy WMM'12, Gent, Belgium: Gent University , 2012, s. 101-119Konferansepaper (Annet vitenskapelig)
    Abstract [en]

    This paper gives an overview of nowadays used simulation models and measurement methods in order to determine iron losses in electrical machinery. The paper provides machine designers and system engineers with an overview of suitable iron loss models applicable for the machine design process and simulations. Furthermore, possible methods for iron loss measurements in electrical machines are presented from ongoing research projects. Besides standard electrical power measurements, iron losses are determined by thermal and magnetic property measurements, taking into account different IEC and IEEE standards.The goal is to emphasize the different possibilities of iron loss measurement methods and possible application areas for electrical machinery.

  • 26.
    Krings, Andreas
    et al.
    KTH, Skolan för elektro- och systemteknik (EES), Elektrisk energiomvandling.
    Nategh, Shafigh
    KTH, Skolan för elektro- och systemteknik (EES), Elektrisk energiomvandling.
    Wallmark, Oskar
    KTH, Skolan för elektro- och systemteknik (EES), Elektrisk energiomvandling.
    Soulard, Juliette
    KTH, Skolan för elektro- och systemteknik (EES), Elektrisk energiomvandling.
    Influence of the Welding Process on the Magnetic Properties of a Slot-less Permanent Magnet Synchronous Machine Stator Core2012Inngår i: Proceedings of the 2012 XXth International Conference on Electrical Machines, IEEE conference proceedings, 2012, s. 1331-1336Konferansepaper (Fagfellevurdert)
    Abstract [en]

    In this paper, the influence of the welding processduring the manufacturing of small, slot-less permanent magnetsynchronous machines (PMSMs) is studied. The focus lies onthe change of the magnetic properties and the iron losses inthin, high quality Si-alloyed electrical steel sheets (NO 20). It isshown that the welding process changes the magnetic materialproperties significantly and increases the specific iron losses.Experimental results are provided for magnetic flux densitiesup to 1.3 T and frequencies in the range of 0.1Hz to 200Hz.

  • 27.
    Krings, Andreas
    et al.
    KTH, Skolan för elektro- och systemteknik (EES), Elektrisk energiomvandling.
    Nategh, Shafigh
    SmartMotor AS, Rolls-Royce Group, Norway .
    Wallmark, Oskar
    KTH, Skolan för elektro- och systemteknik (EES), Elektrisk energiomvandling.
    Soulard, Juliette
    KTH, Skolan för elektro- och systemteknik (EES), Elektrisk energiomvandling.
    Influence of the Welding Process on the Performance of Slotless PM Motors With SiFe and NiFe Stator Laminations2014Inngår i: IEEE transactions on industry applications, ISSN 0093-9994, E-ISSN 1939-9367, Vol. 50, nr 1, s. 296-306Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The influence of the welding process during the manufacturing of small slotless permanent-magnet synchronous machines (PMSMs) is studied in this paper. The focus lies on the change of the magnetic properties in high-quality silicon-iron (SiFe) and nickel-iron (NiFe) electrical steel sheets with thicknesses of 0.1 and 0.2 mm. It is shown that the welding process changes the magnetic material properties significantly and increases the specific iron losses. Experimental results are provided for magnetic flux densities up to 1.5 T and frequencies from quasi-static to 200 Hz. The obtained measurement data is afterward used in finite-element method (FEM) simulations to investigate the influence of the magnetic property changes on the motor performance, particularly with regard to stator core losses.

  • 28.
    Krings, Andreas
    et al.
    KTH, Skolan för elektro- och systemteknik (EES), Elektrisk energiomvandling.
    Nategh, Shafigh
    KTH, Skolan för elektro- och systemteknik (EES), Elektrisk energiomvandling.
    Wallmark, Oskar
    KTH, Skolan för elektro- och systemteknik (EES), Elektrisk energiomvandling.
    Soulard, Juliette
    KTH, Skolan för elektro- och systemteknik (EES), Elektrisk energiomvandling.
    Local Iron Loss Identification by Thermal Measurements on an Outer-Rotor Permanent Magnet Synchronous Machine2012Inngår i: Proceedings of the 15th International Conference on Electrical Machines and Systems (ICEMS 2012), Sapporo: Institution of Electrical Engineers of Japan (IEEJ), 2012, s. 6401970-Konferansepaper (Fagfellevurdert)
    Abstract [en]

    This paper presents the experimental determination of iron losses in an outer-rotor permanent magnet synchronous machine (PMSM) by using an inverse thermal model (ITM) in connection with transient thermal measurements. First, the theory and assumptions lying behind the method are presented. Afterwards, 3D finite element method (FEM) based simulations are used to determine the flux density distribution and iron losses in the magnetic steel parts of the investigated machine. Thermal measurements are conducted to determine local iron losses in the stator tooth tips using the ITM. Finally, measurement and FEM simulation results are compared.

  • 29.
    Krings, Andreas
    et al.
    KTH, Skolan för elektro- och systemteknik (EES), Elektrisk energiomvandling.
    Soulard, Juliette
    KTH, Skolan för elektro- och systemteknik (EES), Elektrisk energiomvandling.
    Experimental characterization of magnetic materials for electrical machine applications2015Inngår i: 2015 IEEE Workshop on Electrical Machines Design, Control and Diagnosis (WEMDCD), IEEE , 2015, s. 85-89Konferansepaper (Fagfellevurdert)
    Abstract [en]

    Most of the volume in classical electrical machinesis occupied by magnetic materials for creating an as good as possible magnetic path. In machines with planar flux paths (2Dgeometries) the material is laminated to reduce eddy current losses in the core. Manufacturers typically supply reference values from Epstein frame measurements as a material performance specification and an easy way for comparison. However, the magnetic flux path in electrical machines is more complex due to rotating magnetic fields passing through the stator (with or without teeth), the rotor, and the airgap. Therefore, other material characterization methods, such as ring core measurements, are more suitable to characterize the magnetic materials for electricalnmachines. This paper gives a short introduction on different methods to characterize magnetic materials and a detailed de-scription of building up a measurement system for characterizingring core samples or electrical machine stator cores. The system isdeveloped with regard to the IEC standard for measurements on magnetic ring core samples and can easily be build up in any lab with a power amplifier and a standard industrial control system equipped with analog input/output interfaces. Finally, reference measurements demonstrate the performance of the system.

  • 30.
    Krings, Andreas
    et al.
    KTH, Skolan för elektro- och systemteknik (EES), Elektrisk energiomvandling.
    Soulard, Juliette
    KTH, Skolan för elektro- och systemteknik (EES), Elektrisk energiomvandling.
    Overview and Comparison of Iron Loss Models for Electrical Machines2010Inngår i: Journal of Electrical Engineering, ISSN 1582-4594, Vol. 10, nr 3, s. 162-169Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    One important factor in the design process and optimization of electrical machines and drives are iron losses in the core. By using new composite materials and low-loss electrical Silicon-Iron (SiFe) steels, the losses in the magnetic flux conducting parts of the machine can be reduced significantly. However, it is necessary to have accurate but also easy implementable iron loss models to take the loss effects into account, preferable already during the first design steps and simulations of new electrical machines.

    The goal of this paper is to give an overview of available iron loss models and to summarize and compare certain models for analytical and numerical machine design methods.

  • 31.
    Krings, Andreas
    et al.
    KTH, Skolan för elektro- och systemteknik (EES), Elektrisk energiomvandling.
    Soulard, Juliette
    KTH, Skolan för elektro- och systemteknik (EES), Elektrisk energiomvandling.
    Overview and Comparison of Iron Loss Models for Electrical Machines2010Konferansepaper (Fagfellevurdert)
    Abstract [en]

    One important factor in the design process and optimization of electrical machines and drives are iron losses in the core. By using new composite materials and low-loss electrical SiFe steels, the losses in the magnetic flux conducting parts of the machine can be reduced significantly. However, it is necessary to have accurate but also easy implementable iron loss models to take the loss effects into account, preferable already during the first design steps and simulations of new electrical machines.

    The goal of this paper is to give an overview of available iron loss models and to summarize and compare certain models for analytical and numerical machine design methods.

  • 32.
    Krings, Andreas
    et al.
    KTH, Skolan för elektro- och systemteknik (EES), Elektrisk energiomvandling.
    Soulard, Juliette
    KTH, Skolan för elektro- och systemteknik (EES), Elektrisk energiomvandling.
    Wallmark, Oskar
    KTH, Skolan för elektro- och systemteknik (EES), Elektrisk energiomvandling.
    Influence of PWM Switching Frequency and Modulation Index on the Iron Losses and Performance of Slot-less Permanent Magnet Motors2013Inngår i: Proceedings of the 16th International Conference on Electrical Machines and Systems, Busan: KIEE - The Korean Institute of Electrical Engineering , 2013, s. 474-479Konferansepaper (Fagfellevurdert)
    Abstract [en]

    This paper investigates the influence of switching frequency and modulation index on the iron losses in thin silicon-iron (SiFe) lamination sheets of a small slot-less permanent magnet synchronous machine (PMSM). First, measurements are conducted on one welded and one non-welded stator core for switching frequencies between 1 kHz and 20 kHz and modulation indices of 0.4, 0.7, and 0.9, keeping constant fundamental flux density peak values. The obtained measurement data is afterwards used in finite element method (FEM) simulations to investigate the switching frequency influenceon the performance of the PMSM.

  • 33.
    Krings, Andreas
    et al.
    ABB AB Corporate Research, Sweden .
    Soulard, Juliette
    ABB AB Corporate Research, Sweden .
    Wallmark, Oskar
    ABB AB Corporate Research, Sweden .
    PWM Influence on the Iron Losses and Characteristics of a Slot-less Permanent Magnet Motor with SiFe and NiFe Stator Cores2015Inngår i: IEEE transactions on industry applications, ISSN 0093-9994, E-ISSN 1939-9367, Vol. 51, nr 2, artikkel-id 6891228Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    This paper investigates the influence of switching frequency and modulation index combined with welding on the iron losses in thin silicon-iron and nickel-iron lamination sheets of a small slot-less permanent magnet synchronous machine. First, measurements are conducted on welded and non-welded stator ring cores for switching frequencies between 1 kHz and 20 kHz and modulation indices of 0.4, 0.7, and 0.9, keeping constant fundamental flux density peak values. This is possible by changing the DC link voltage of the inverter. The obtained measurement data is afterwards used in finite element method (FEM) simulations to investigate the inverter influence on the performance of the permanent magnet synchronous machine.

  • 34.
    Lefevre, Louis
    et al.
    KTH, Skolan för elektro- och systemteknik (EES), Elektrisk energiomvandling.
    Soulard, Juliette
    KTH, Skolan för elektro- och systemteknik (EES), Elektrisk energiomvandling.
    Nee, Hans-Peter
    KTH, Skolan för elektro- och systemteknik (EES), Elektrisk energiomvandling.
    Design procedure for Line-Start Permanent Magnet Motors2000Inngår i: Proc. of the IEEE Nordic Workshop on Power and Industrial Electronics, Aalborg, Denmark, June 2000., 2000Konferansepaper (Fagfellevurdert)
  • 35. Libert, Florence
    et al.
    Soulard, Juliette
    KTH, Tidigare Institutioner, Elektrotekniska system.
    Design Study of a Direct-Driven Surface Mounted Permanent Magnet Motor for Low Speed Application2003Inngår i: Proceedings of Symposium on Advanced Electromechanical Motion Systems (Electromotion), 2003Konferansepaper (Annet vitenskapelig)
    Abstract [en]

    The goal of the study presented in this paper is to find a suitable direct-driven Surface Mounted Permanent Magnetmotor to replace an induction motor and its gearbox for an industrial application requiring 5 kW and 50 rpm. Thedesign process is first describedwith some discussion of the calculation of the flux density in the airgap. Distributedwindings with one slot per pole per phaseand concentratedwindings with fractional slot number per pole per phase, are then investigated. Itisshown that designs with a high number of poles, concentratedwindings and an irregular distribution of slots give the best performance.

  • 36. Libert, Florence
    et al.
    Soulard, Juliette
    KTH, Tidigare Institutioner, Elektrotekniska system.
    Design Study of Different Direct-Driven Permanent-Magnet Motors for a Low Speed Application2004Konferansepaper (Annet vitenskapelig)
  • 37. Libert, Florence
    et al.
    Soulard, Juliette
    KTH, Skolan för elektro- och systemteknik (EES), Elektrisk energiomvandling.
    Design Study of Low-Speed Direct-Driven Permanent-Magnet Motors with Concentrated Windings2005Konferansepaper (Annet vitenskapelig)
  • 38. Libert, Florence
    et al.
    Soulard, Juliette
    KTH, Tidigare Institutioner, Elektrotekniska system.
    Investigation on Pole-Slot Combinations for Permament Magnet Machines with Concentrated Windings2004Konferansepaper (Fagfellevurdert)
  • 39.
    Libert, Florence
    et al.
    KTH, Skolan för elektro- och systemteknik (EES), Elektriska maskiner och effektelektronik (stängd 20110930).
    Soulard, Juliette
    KTH, Skolan för elektro- och systemteknik (EES), Elektriska maskiner och effektelektronik (stängd 20110930).
    Manufacturing Methods of Stator Cores with Concentrated Windings2006Inngår i: The 3rd IET International Conference on Power Electronics, Machines and Drives, 2006, s. 676-680Konferansepaper (Annet vitenskapelig)
    Abstract [en]

    The purpose of this paper is to investigate the difficulties in manufacturing a stator core with concentrated windings. The existing solutions are compared in terms of cost, required equipment for the production and performance of the permanent-magnet (PM) motor. A 1 kW 28-pole PM motor with an outer diameter of 400mm, designed for a low-speed direct-driven application is taken as an example

  • 40.
    Magnussen, Freddy
    et al.
    KTH, Skolan för elektro- och systemteknik (EES), Elektriska maskiner och effektelektronik (stängd 20110930).
    Chin, Yung-Kang
    KTH, Tidigare Institutioner, Elektrotekniska system.
    Soulard, Juliette
    KTH, Tidigare Institutioner, Elektrotekniska system.
    Broddefalk, A.
    Eriksson, Sture J A
    KTH, Skolan för elektro- och systemteknik (EES), Elektriska maskiner och effektelektronik (stängd 20110930).
    Sadarangani, Chandur
    KTH, Tidigare Institutioner, Elektrotekniska system.
    Iron losses in salient permanent magnet machines at field-weakening operation: COVERING THEORY TO PRACTICE2004Inngår i: CONFERENCE RECORD OF THE 2004 IEEE INDUSTRY APPLICATIONS CONFERENCE, VOLS 1-4: COVERING THEORY TO PRACTICE, NEW YORK, NY: IEEE , 2004, s. 40-47Konferansepaper (Fagfellevurdert)
    Abstract [en]

    Permanent magnet machines for electric vehicles are often designed with a magnetic saliency to improve the torque generation as a result of the reluctance torque at field-weakening operation. The armature reaction is pronounced in such operation, leading to extensive magnetic field harmonics in the teeth and consequently iron losses. This paper analyses the iron losses in two designed machine topologies, inset and interior permanent magnet rotor structures, by measurements and finite element method computations. The measurements and calculations are performed on three prototypes-one with an in set design and two with an equal interior design, but different laminated stator core sheet thickness of 0,35 and 0,20 mm, respectively. The three machines have the same stator designs and water-cooled housings.

  • 41. Meessen, K. J.
    et al.
    Thelin, P.
    Soulard, Juliette
    KTH, Skolan för elektro- och systemteknik (EES), Elektriska maskiner och effektelektronik.
    Lomonova, E. A.
    Inductance calculations of permanent-magnet synchronous machines including flux change and self- and cross-saturations2008Inngår i: IEEE transactions on magnetics, ISSN 0018-9464, E-ISSN 1941-0069, Vol. 44, nr 10, s. 2324-2331Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Accurate inductance calculation of permanent-magnet synchronous machines is a relevant topic, since the inductances determine a large part of the electrical machine behavior. However, the inductance calculation, as well as the inductance measurement, is never a completely straightforward task when saturation occurs. In this paper, the total flux in the d and q axes are obtained from finite-element method or measurements and therefore include saturation and cross-couplings. The inductances are obtained from analytical post-processing based on an equivalent magnetic circuit. The originality of this method is that it accommodates the changes in the magnet flux and the inductances with the level of saturation. The resulting inductance values are the ones seen by the converter or the grid, as found by a more accurate approach.

  • 42.
    Meier, Florence
    et al.
    KTH, Skolan för elektro- och systemteknik (EES), Elektriska maskiner och effektelektronik.
    Meier, Stephan
    KTH, Skolan för elektro- och systemteknik (EES), Elektriska maskiner och effektelektronik.
    Soulard, Juliette
    KTH, Skolan för elektro- och systemteknik (EES), Elektriska maskiner och effektelektronik.
    Emetor: An educational web-based design tool for permanent-magnet synchronous machines2009Inngår i: ICEM: 2008 INTERNATIONAL CONFERENCE ON ELECTRICAL MACHINES, NEW YORK: IEEE , 2009, s. 2238-2243Konferansepaper (Fagfellevurdert)
    Abstract [en]

    An educational web-based design tool for permanent-magnet synchronous machines (PMSM) is presented in this article. This tool, named Emetor, has been developed to be used in an undergraduate course on permanent-magnet machines. The technical aspects behind the tool, such as the PMSM's design procedure and the program architecture are presented. The benefits of Emetor in an educational environment are described. Different learning activities are presented to illustrate the potential of Emetor, as well as its suitability for education.

  • 43.
    Meier, Florence
    et al.
    KTH, Skolan för elektro- och systemteknik (EES), Elektriska maskiner och effektelektronik.
    Soulard, Juliette
    KTH, Skolan för elektro- och systemteknik (EES), Elektriska maskiner och effektelektronik.
    Analysis of Flux Measurements on a PMSM With Non-Overlapping Concentrated Windings2008Inngår i: 2008 IEEE INDUSTRY APPLICATIONS SOCIETY ANNUAL MEETING, 2008, s. 2090-2097Konferansepaper (Fagfellevurdert)
    Abstract [en]

    In this paper, measurements of the magnetic flux in a permanent-magnet synchronous machine (PMSM) with non-overlapping concentrated windings are analyzed. Flux leakage, inductances and stator iron losses are investigated from measurements performed at open-circuit, blocked-rotor, and load conditions, respectively. Comparisons of the measurements with the corresponding 3D finite-element (FE) simulations allow validating thoroughly the FE model. The zigzag leakage flux flowing from one magnet to another through a tooth tip, which is characteristic for PMSMs with concentrated windings, is highlighted and its effect on the stator iron losses is investigated.

  • 44.
    Meier, Florence
    et al.
    KTH, Skolan för elektro- och systemteknik (EES), Elektriska maskiner och effektelektronik (stängd 20110930).
    Soulard, Juliette
    KTH, Skolan för elektro- och systemteknik (EES), Elektriska maskiner och effektelektronik (stängd 20110930).
    dq Theory Applied to a Permanent Magnet Synchronous Machine with Concentrated Windings2008Inngår i: 4th IET International Conference on Power Electronics, Machines and Drives (PEMD 2008), 2008, s. 194-198Konferansepaper (Fagfellevurdert)
    Abstract [en]

    In this paper, dq theory is applied to a surface-mounted permanent magnet synchronous machine with non-overlapping concentrated windings. Although the assumption of sine-distributed windings is violated, it is shown with theory and measurements, that the dq model is reliable for torque and voltage calculations of the loaded machine.

  • 45.
    Millinger, Jonas
    et al.
    KTH, Skolan för elektro- och systemteknik (EES), Elkraftteknik.
    Soulard, Juliette
    KTH, Skolan för elektro- och systemteknik (EES), Elkraftteknik.
    Wallmark, Oskar
    KTH, Skolan för elektro- och systemteknik (EES), Elkraftteknik.
    Influence of Shaft Relative Permeability on Rotor Losses in 2-pole Slotless High-Speed Motor2016Inngår i: Proceedings - 2016 22nd International Conference on Electrical Machines, ICEM 2016, Institute of Electrical and Electronics Engineers (IEEE), 2016, s. 405-411, artikkel-id 7732558Konferansepaper (Fagfellevurdert)
    Abstract [en]

    This paper presents a time-efficient transient numerical method for three-dimensional analysis of rotor losses in a three-phase 2-pole high-speed permanent-magnet synchronous machine. The motor has axially stacked ring shaped permanent magnets (PM). The influence of shaft material properties on rotor harmonic losses and loss distribution between the rotor shaft and magnets is investigated in the frequency range 10100 kHz. It is found that the shaft magnetic properties have a significant impact not only on the total rotor losses, but on the magnet losses and inductance as well.

  • 46.
    Millinger, Jonas
    et al.
    KTH, Skolan för elektroteknik och datavetenskap (EECS), Elkraftteknik. KTH.
    Wallmark, Oskar
    KTH, Skolan för teknikvetenskap (SCI), Farkost och flyg.
    Soulard, Juliette
    KTH.
    High Frequency Characterization of Losses in FullyAssembled Stators of Slotless PM Motors2018Inngår i: IEEE transactions on industry applications, ISSN 0093-9994, E-ISSN 1939-9367Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Abstract—The recent emerge of wide band-gap (WBG) powertransistors enables higher switching frequencies in electricalmotor drives. Their full utilization from a system point ofview requires quantification of the corresponding time-harmonicmotor losses. As an initial step, this paper presents a uniquestudy of stator losses for three different commercially availablenon-oriented silicon-iron (SiFe) steel grades (with laminationthicknesses 0.1, 0.2 and 0.3 mm). The investigations cover awide frequency range (10-100 kHz) at different levels of DC-bias(up to 1.6 T). Iron losses are identified from measurements onfully assembled stators, deploying a novel technique. By utilizingfully assembled stators, no additional samples are required.Manufacturing influence is inherently incorporated. Results showthat measured iron losses are twice as high at 10 kHz comparedto Epstein test results, which emphasizes the need to incorporatemanufacturing influence on iron losses at high frequencies. Thelevel of DC-bias is also observed to have a significant impacton iron losses (up to 30 %). Even though thinner laminationsare known for reducing iron losses, the reduction is much lowerthan anticipated in the studied frequency range due to skin effect.Using 0.1 mm lamination gauge instead of 0.3 mm reduces lossesby 50 % at 10 kHz, while the same substitution at 100 kHz onlyreduces losses by 30 %. Future work includes loss separation incomplete converter-fed machines.

  • 47. Nee, Hans-Peter
    et al.
    Lefevre, L.
    Thelin, P.
    Soulard, Juliette
    KTH, Tidigare Institutioner, Elektrotekniska system.
    Determination of d and q reactances of permanent-magnet synchronous motors without measurements of the rotor position2000Inngår i: IEEE transactions on industry applications, ISSN 0093-9994, E-ISSN 1939-9367, Vol. 36, nr 5, s. 1330-1335Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The interest in permanent-magnet synchronous motors:(PMSMs) is increasing in a wide area of applications. Since most PMSMs will operate without a shaft sensor in the future, valuable: information for experimental determination of machine parameters will be lost,In this paper, therefore, a method is presented where the induced EMF and the d-axis reactance are determined in a no-load test and the q-axis reactance is determined in a load test. The load angle delta is determined from the load test by means of a new analytical method. In this way, no separate measurement of the load angle is required. The method is especially suitable for line-start PMSMs which normally operate with negative d-axis current and, therefore, are not saturated in the d-axis flux paths. Moreover, the method is very simple to carry out for any laboratory technician, since the only tests that have to be made are standard tests which are made on standard induction motors on a regular basis.

  • 48. Salminen, Pia
    et al.
    Libert, Florence
    KTH, Skolan för elektro- och systemteknik (EES), Elektriska maskiner och effektelektronik (stängd 20110930).
    Pyrhönen, J.
    Soulard, Juliette
    KTH, Skolan för elektro- och systemteknik (EES), Elektriska maskiner och effektelektronik (stängd 20110930).
    Torque Ripple of Permanent Magnet Machines with Concentrated Windings2005Inngår i: Proceedings of the 6th International Symposium on Electromagnetic Fields in Mechatronics, Electrical and Electronic Engineering, (ISEF 2005), 2005Konferansepaper (Fagfellevurdert)
    Abstract [en]

    In the present paper, the torque ripples of surface mounted PM machines with different concentrated windings are investigated. The goal is to analyze the torque ripple for different concentrated windings and check how the ripple can be minimized by changing the geometry of the design. The slot number and pole number are varied. The effect of the magnet width and the slot opening width on the torque ripple of these motors is investigated.

  • 49. Smeets, Johan
    et al.
    Soulard, Juliette
    KTH, Skolan för elektro- och systemteknik (EES), Elektriska maskiner och effektelektronik (stängd 20110930).
    Lomonova, Elena
    Thermal Analysis of a Winding Turn-to-Turn Fault in PM Synchronous Machine2010Inngår i: 19th International Conference on Electrical Machines, ICEM 2010, 2010Konferansepaper (Fagfellevurdert)
    Abstract [en]

    This paper presents a detailed lumped parameter (LP) thermal model of an armature slot in a permanent magnet synchronous machine for traction applications. The model is used to investigate the temperature distribution in the slot after a turn-to-turn failure occurs. Steady-state analyses are conducted and a good agreement is found with FEM thermal simulations. The LP model is modified into a transient model and transient thermal analysis are conducted to predict the processing damage in the slot, which eventually might lead to a turn-to-tooth (ground) failure.

  • 50.
    Soulard, Juliette
    KTH, Skolan för elektro- och systemteknik (EES), Elektriska maskiner och effektelektronik (stängd 20110930).
    Framtidens elektriska maskiner skapas (nästan) direkt i datorn2007Inngår i: ERA : elektricitetens rationella användning, ISSN 0013-9939, nr 1, s. 70-Artikkel i tidsskrift (Annet vitenskapelig)
12 1 - 50 of 62
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