TY - JOUR N2 - The classic relationships concerning the harmonic content in the air gap field of three-phase machines are presented in form of series of rotating waves. The same approach is applied to modeling of permanent magnet motors with fractional phase windings. All main reasons of non-sinusoidal shape of flux density distribution, namely, magnets’ shape and their placement, slotting, magnetic saturation and eccentricity are also related to their counterparts in modal-frequency spectrum. The Fourier 2D spectrum of time-stepping finite element solution is confronted with results of measurements, with special attention paid to accuracy of both methods. L1 - http://journals.pan.pl/Content/84885/PDF/03_paper.pdf L2 - http://journals.pan.pl/Content/84885 PY - 2014 IS - No 1 March EP - 46 DO - 10.2478/aee-2014-0003 KW - electromagnetic fields KW - waves permanent magnet machines KW - air gap magnetic flux KW - spectral analysis KW - finite element method A1 - Pawel Witczak A1 - Kubiak, Witold A1 - Lefik, Marcin A1 - Szulakowski, Jacek PB - Polish Academy of Sciences VL - vol. 63 DA - 2014 T1 - Modal-frequency spectrum of magnetic flux density in air gap of permanent magnet motor SP - 29 UR - http://journals.pan.pl/dlibra/publication/edition/84885 T2 - Archives of Electrical Engineering ER -