A dynamoelectric machine combining the functions of an exciter, a turning motor,
and a starting motor for a turbine. The machine operates in a first mode where
the slip between a first stator winding and a first armature winding is positive
and thus the magnetic fields interact and operate as a motor to turn the turbine.
In a second mode the slip is negative as the turbine turns the shaft and the first
stator winding and the first armature operate as an exciter for supplying excitation
to the rotating field winding of a main generator.