Machine Question No.21 - Output voltage of generator
It is well known that, if an Alternator is connected with Grid its (alternator) voltage can not be change and it follows the grid voltage but i've seen that when its excitation changes its voltage also changes, why?
Author : Yogi - From: India
Wed, July 22nd, 2009 - 18:44
It is impossible; the output voltage of generator is fixed by constant voltage of grid indeed they are one voltage that we can measure it in generator output terminals. Of course the internal emf of alternator which you cannot measure it may be changed due to excitation current or load current phase angle variation.
Author : Hamid - From: Iran
Fri, January 13th, 2012 - 18:03
if excitation changes, the magnitude of flux density also changes and we know that generated voltage is directly proportional to the flux density it also changes.... over excited alternator delivers reactive power due to demagnetization effect of armature.... reactive power will be delivered to load and we know that reactive power flows only when their is voltage difference...