Answer / shiv

when there is no excitation ther will be no magnetic field
setup as a result of which no EMF will be induced which
means there is no output available from the generator.

Answer / sunil kumar sinha

If the excitation of generator is lost, it will continue to
generate power by taking excitation from grid. The flux
will pass through the surface of rotor which will cause
excessive heating of rotor. Further, around moon slots the
current will jump and may cause over heating around moon
slots of generator rotor beyond limits.

There is possibility of insulation failure of rotor winding
if operated for longer period at higher load, hence loss of
excitation relay is a must protection for generator. This
relay is further monitered by excitation supervision relay
in many of sets.

Answer / jagatheesan k

if excitation lost generator will draw power from grid(ie.,it draws reactive power from grid)and run as induction generator(runs at a speed more than synchronous speed) .

Answer / gunnam santosh

if excitation is removed also it will induce a small emf as
we basically use eletromagnets it contains some residual flux.

Answer / rajasekhar

am takin a synchronous generator
in general a syn. gen operates on prinicipal of synchronism
which obtains when we excite it with any other source ...if
directly excitation is lost there wil not be any alternating
flux which plays a main role with out no operation takes place

Answer / om prakash

If the excitation of generator is lost, than emf will not
be induced in alternator. Than we need to do excited
alternator by Outer DC voltage.

Answer / umesh

in the generator the exitation is the main source to
genrate the EMF, whenever the exitatio got lost then there
is no magnetic field, NO EMF will be built,

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