TY - CHAP A1 - Grauvogl, Dominik A1 - Stauder, Peter A1 - Hopfensperger, Bernhard A1 - Gerling, Dieter T1 - Multiphysics Design of a Wound Field Synchronous Machine with Magnetic Asymmetry T2 - Proceedings of the 2021 IEEE International Electric Machines & Drives Conference (IEMDC): 17-20 May 2021, Hartford, CT, USA N2 - In this paper a multiphysics development method is used for designing a novel wound field synchronous machine of the future generation of high voltage traction drives. This method covers the domains of electromagnetics, the mechanical strength, thermal behavior and the magnetic noise. It is shown that the proposed novel asymmetric design with a circular flux barrier in combination with an asymmetric pole offset is fulfilling the requirements according to performance and torque ripple. A fatigue strength rotor mechanic concept is included. A hybrid cooling concept consisting of a water jacket cooled stator and air cooled rotor ensures the needed continuous power. Unacceptable noise levels are excluded by investigating the equivalent radiated power (ERP) level due to radial forces in the air gap. Finally, the multi-physical workflow resulted in a fully developed component with a high degree of maturity. KW - air cooling KW - wound field synchronous machine KW - cooling concept KW - fatigue limit KW - flux barrier Y1 - 2021 U6 - https://doi.org/10.1109/IEMDC47953.2021.9449564 ER - TY - CHAP A1 - Grauvogl, Dominik A1 - Krabinski, Jeffrey A1 - Stauder, Peter A1 - Hopfensperger, Bernhard A1 - Gerling, Dieter T1 - NVH Comparison of a Novel Wound Field Synchronous Machine with Magnetic Asymmetry with a PSM for a HV Electric Drive T2 - 2021 JSAE Annual Congress (Spring) Proceedings; online meeting (No.76-21) N2 - This paper shows how magnetic noises can be reduced with a wound field synchronous machine (WFSM) with magnetic asymmetry compared to a permanent magnet synchronous machine (PSM), operating at base speed range and full load. In order to reproduce a real noise behavior, the two rotor types are operated in a complete electric drive unit (EDU) consisting of an electric motor, gearbox, inverter and overall housing. In the concept study, the noise characteristics of the two electric machines is evaluated and compared via mechanical finite element method (FEM) simulations using the equivalent radiated power (ERP) level and Campbell diagrams. Furthermore, it is shown that critical frequency orders can already be identified by the analysis of the magnetic force density from the electromagnetic design without computationally intensive ERP calculations. In this context, the ERP investigations have shown that the unique feature of the magnetically asymmetric WFSM is the reduction of the slot harmonics. At the current state of the art, the slot harmonics can only be reduced with a rotor skewing. The disadvantage of this is a reduction in performance and a more expensive production. It is also remarkable that the magnetic asymmetry reduces the slot harmonics more than the rotor skewing in the PSM. In addition, both machines are still considered with a short-pitched stator winding to optimize the overall noise level by reducing the 24th frequency order. KW - Elektroantrieb KW - Synchronmaschine KW - traction drive system KW - NVH KW - e-axle KW - magnetic asymmetry Y1 - 2021 UR - https://tech.jsae.or.jp/paperinfo/en/content/p202101.343/ PB - JSAE ER -