The error voltage represents {TAIL ~ the magnitude} and {HEAD ~ sign} of the difference between the actual and the required common power component 
The error voltage represents { TAIL ~ the magnitude } and { HEAD ~ sign } of the difference between the actual and the required common power component
OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL OTH HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH