Electrically compensated constant speed drive with prime mover start capability

摘要

An electrically compensated constant speed drive includes a mechanical differential having first and second input shafts and an output shaft wherein a prime mover is coupled to the first input shaft, a brushless generator is coupled to the differential output shaft and includes a control permanent magnet generator (PMG) and a main generator which develops output power and a speed compensation link is coupled between the control PMG and the second differential shaft. The speed compensation link includes a dynamoelectric machine coupled to the second differential input shaft and a power converter which interconnects armature windings of the control PMG and electrical power windings of the dynamoelectric machine. A generator control unit controls the flow of power between the control PMG and the dynamoelectric machine so that the dynamoelectric machine develops compensating speed of a magnitude sufficient to maintain the output shaft of the differential at a desired speed so that the brushless generator develops constant frequency AC power. The present constant speed drive is lighter and smaller than prior electrically compensated constant speed drives.