Unconventional windings for traction motors in electric vehicles
Creators: name: Raziee, Seyed Morteza
Publisher: name: Hannover : Institutionelles Repositorium der Gottfried Wilhelm Leibniz Universität Hannover
Year: 2024
Subjects: subject: combined star-delta windings
subject: combined star-polygon windings
subject: single-layer fractional-slot distributed windings
subject: winding design
subject: star of slots
subject: winding index
subject: winding analysis
subject: winding factor
subject: harmonic leakage factor
subject: harmonic leakage factor of the zero sequence
subject: rotating field theory
subject: winding function approach
subject: symmetrical component analysis
subject: noise vibration and harshness (NVH)
subject: contains research data
subject: kombinierte Stern-Dreieck Wicklungen
subject: kombinierte Stern-Vieleck Wicklungen
subject: Einschicht-Bruchlochwicklungen
subject: Wicklungsentwurf
subject: Nutenstern
subject: Winding Index
subject: Wicklungsanalyse
subject: Wicklungsfaktor
subject: Oberwellenstreuung
subject: Oberwellenstreuung der Nullkomponente
subject: Drehfeldtheorie
subject: Wicklungsfunktion
subject: symmetrische Komponenten
subject: Noise-Vibration-Harshness (NVH)
subject: enthält Forschungsdaten
subject: Dewey Decimal Classification::600 | Technik::620 | Ingenieurwissenschaften und Maschinenbau::621 | Angewandte Physik::621,3 | Elektrotechnik, Elektronik

description: In this dissertation, combined star-delta windings and single-layer fractional-slot distributed windings are mainly evaluated, which are incorporated within a cage-induction machine and an electrically excited synchronous machine, respectively. Both electrical machines were designed as prototypes for automotive applications. The combined star-polygon windings feature an increased fundamental winding factor and a decreased harmonic leakage factor. These characteristics make them suitable for traction applications to increase the torque density of electrical machines, to widen the field-weakening region and to reduce the noise, vibration, and harshness (NVH). Almost every winding, including some single-layer fractional-slot distributed windings, can be connected in combined star-polygon. Due to the undesired magnetic coupling between the additional spatial harmonics generated by the winding and the low-resistance rotor circuit, the single-layer fractional-slot distributed windings are only suitable for synchronous machines without electrically conductive solid rotors or damper windings. Besides, they do not need an additional insulation layer inside the slots to isolate different coil sides compared to the double-layer windings. This provides an additional space inside the slots, which can be used to increase the slot-filling factor. Moreover, an increased slot-filling factor and a reduced number of insulation layers improve the effectiveness of the cooling system. Nevertheless, a single-layer compared to a double-layer fractional-slot distributed windings excites additional spatial harmonics, which can affect the performance and the NVH behavior of synchronous machines. Therefore, the performance and the NVH results measured on comparable electrically excited synchronous machines are studied in detail. In contrast to other winding types, the star of slots is found being insufficient to design some single-layer fractional-slot distributed windings. Thus, part of this work deals with the systematic design method of fractional-slot distributed windings based on the winding index. Through the analyses of this work, some analytical methods such as calculation equations of the winding factor are developed and the harmonic leakage factor of the zero sequence is derived. Besides, the rotating field theory is integrated with the winding function approach to consider the possible unipolar flux densities, the stator and rotor slotting, the static and dynamic air-gap eccentricities, the magnetic saturation and the stator and rotor magnetic anisotropies. The Fourier series of the measured terminal currents, voltages and accordingly the instantaneous powers bring some additional information, which can be applied to the rotating field theory to explain the corresponding magnetic NVH excitations.