under steay state:
P= (E V sinδ)/ X
change in load on motor, δ adjust to new value
rotor oscillate about its final equilibrium load angle called hunting.
sudden change in load
fault in supply system
sudden change in field current
using damper bar
all day efficiency is ratio of energy output to the energy input taken over 24 hour period.
design distribution transformer for max. efficiency occurring at the avarage output power.
performance of distribution transformer represent by all day efficiency.