A multi phase generator has {TAIL ~ a separately excited shunt field} which is controlled by {HEAD ~ a voltage regulator} 
A multi phase generator has { TAIL ~ a separately excited shunt field } which is controlled by { HEAD ~ a voltage regulator }
OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD