Modeling of End-Space Convection Heat-Transfer for Internal and External Rotor PMSMs With Fractional-Slot Concentrated Windings

Modeling of convection heat-transfer at the end-windings for thermal networks using lumped-parameters has been widely discussed in literature. Unfortunately, resulting coefficients are highly influenced by end-winding shape, area vicinity end-windings, cooling method this region (if any), as well size and power machine. This makes it extremely difficult designer to choose a suitable coefficient analysis during design stage an electric motor. A methodology obtain fractional-slot concentrated winding permanent-magnet synchronous motors is proposed article. Machine designs with both internal external rotors will be considered. The experimental tests required model characterization described detail. In article, general expressions between housing end-caps rotor designs. Differences observed results reported literature also discussed.