High performance disk alternators

The basic concept, characteristics, and current status of flywheel-disk alternators are examined. The alternator should generate 15 kW/Kg continuously and about 100 kW/kg for one second pulses. The machine can operate at very high voltages a frequencies and requires no output brushes, and both its excitation and output currents can be controlled electronically. The disk alternators contain over 50% useful conductor in the form of petal-shaped layers to form a flywheel disk capable of withstanding rotation at maximum speed and deceleration at maximum rate. Particular attention is given to three machines under development: a single-disk machine for the 9 MJ antiarmor system; a counterrotating, electrically driven, second-generation machine; and a continuous-duty, 20 MW machine. >