Stator for variable speed electric motor - has 2 pole pairs with associated field winding connected in series with armature

摘要

The stator has two pairs of magnetic poles, one pole set energised by a field winding (5) in series with the armature the other pole set provided by permanent magnet segments. The transverse armature field, the two pole sets and the permanent magnet segments are selected. A uniform braking torque is obtained over all rotation ranges, until the armature is brought to a standstill. Pref. the pole field centre line for the armature extends through the geometric neutral zone between the two poles. ADVANTAGE - Ensures uniform braking torque.