Sharif University of Technology Scientia Iranica 1026-3098 Articles in Press 2025 01 12 Minimization of Space Harmonics for Fractional-Slot Windings of Multi-Speed Wound Rotor Resolvers 23789 10.24200/sci.2025.64997.9238 EN Payam MohammadAli Rezayi Electrical Engineering Department, Sharif University of Technology, Tehran, Iran Farid Tootoonchian Electrical Engineering Department, Iran University of Science and Technology, Tehran, Iran Journal Article 2024 07 22 High efficiency PM machines are usually built with high number of poles to meet high power density, and low torque ripple requirements. Their electronic commutation relies on the absolute rotor position data. Therefore, the resolver's pole numbers must equal the PM's pole numbers. Achieving multi-speed performance using traditional winding configurations needs high number of slots. For the limited outer diameter and the size of the sensor, it is limited by the teeth’s mechanical strength. Therefore, Fractional-Slot Concentrated Winding is proposed for multi-speed resolvers. However, FSCWs suffer from high sub-harmonics which cause high position-error of the sensor. To suppress the undesirable harmonics, usually multi-layer winding configuration is employed. Increasing the number of winding layers leads to increase the complexity of the mass production, as well as increasing the possibility of windings’ fault. Hence, in this paper a new technique based on using flux barriers in the stator core is proposed. Three different shapes are presented for the flux barriers. Then, the sensor’s performance equipped by 2- and 4-layer FSCWs, with and without different flux barriers in the stator core, are evaluated using finite-element method. Finally, three prototypes are built and tested. The measured results verify the success of the proposed techniques. https://scientiairanica.sharif.edu/article_23789_19fb67af65debae62bf2d5403715b051.pdf