Unconventional Windings for Traction Motors in Electric Vehicles

Autor: Seyed Morteza Raziee

ISBN: 978-3-95900-938-6

Dissertation, Leibniz Universität Hannover, 2024

Herausgeber der Reihe: Bernd Ponick, Axel Mertens

Band-Nr.: IAL 04/2024

Umfang: 214 Seiten, 138 Abbildungen

Schlagworte: combined star-delta windings, single-layer fractional-slot distributed windings, symmetrical component analysis, harmonic leakage factor

Kurzfassung: This dissertation contains analytical, simulation and measurement results to analyze combined star-delta windings and single-layer fractional-slot distributed windings (FSDWs), including winding design methods, winding, performance and noise-vibration-harshness (NVH) analyses as well as analytical equations for the determination of winding and harmonic leakage factors.
The measurement results on a cage induction machine show marginal efficiency improvements due to using a combined star-delta winding even without improving magnetic and electric circuits. In contrast to the efficiency, the torque density of the electrically excited synchronous machine (EESM) with the single-layer FSDW deteriorated compared to the comparable EESM with the double-layer FSDW under the same current combinations of maximum torque per Ampere. However, the NVH analysis of both EESMs shows similar dominant sidebands. Based on the rotating field theory applied to the measured currents and the Fourier analysis of the instantaneous powers, the similar NVH behavior is due to, e.g., the number of parallel paths associated with non-idealities such as mixed air-gap eccentricities and some even harmonics excited by inverters.