Salient-pole permanent-magnet alternators for high-speed drive

MODERN prime movers, especially turbines, and new applications such as missile auxiliary-power units, have established requirements for reliable, efficient, high-speed machines for the generation of electric energy. The specific feature of the permanent-magnet alternator, i.e., elimination of the wound field and, hence, external excitation and slip rings, makes this type of machine superior to conventional machines for these applications. Reliability is enhanced by the elimination of arcing contacts which cause radio interference, brush operating difficulties at high altitudes, and explosion danger in confined, fuel-laden atmospheres.