Title :
Strand-level proximity losses in PM machines designed for high-speed operation
Author :
Reddy, P.B. ; Zhu, Z.Q. ; Han, Seok-Hee ; Jahns, T.M.
Author_Institution :
Dept. of Electr. & Comput. Eng., Univ. of Wisconsin-Madison., Madison, WI
Abstract :
The stator windings of surface PM synchronous machines with fractional-slot concentrated windings are vulnerable to high proximity losses when operated at high speeds due to their typically high pole numbers and resulting high electrical frequencies. The limitations of an existing 1-D flux density model are demonstrated and an improved 2-D analytical model is introduced for estimating flux densities and stand-level proximity losses inside the slots. The 2-D analytical model is shown to provide good matches with finite element analysis for the predicted flux densities and proximity losses inside a rectangular slot with a variable slot opening and electrical frequency.
Keywords :
finite element analysis; machine theory; magnetic leakage; permanent magnet machines; stators; synchronous machines; 2D analytical model; AC losses; PM machines; brushless machines; finite element analysis; fractional-slot concentrated windings; high-speed operation; stator windings; strand-level proximity losses; surface permanent magnet synchronous machines; Analytical models; Conductors; Finite element methods; Frequency; Laplace equations; Machine windings; Magnetic flux; Scanning probe microscopy; Stator windings; Synchronous machines; AC losses; brushless machines; high speed; permanent magnet; proximity loss;
Conference_Titel :
Electrical Machines, 2008. ICEM 2008. 18th International Conference on
Conference_Location :
Vilamoura
Print_ISBN :
978-1-4244-1735-3
Electronic_ISBN :
978-1-4244-1736-0
DOI :
10.1109/ICELMACH.2008.4800172