The availability of new high-field permanent-magnet materials has crea
ted opportunities for novel topologies of electrical machines with adv
antageous characteristics such as high efficiency and good power/weigh
t ratio. A disc-type arrangement, with slotless winding and axially-di
rected flux in the air gap, has particularly short axial length and is
well suited for system integration as either generator or motor. Appl
ications include auxiliary power units, electric vehicle drives and wi
nd power generation.