what will happen when excitation of a synchronous machine
is suddenly reduce to zero when it is running at full
load..??

Answer Posted / rakesh kumar

in case of a synchronous motor once the excitation is cut
off , then the motor starts to run as an induction motor,
this is because a synchronous motor by itself is not self
starting , and is first started as a squirrel cage
induction motor , once the motor attains about 95% of
synchronous speed then the excitation is applied due to
which the the copper bars are effectively removed from the
circuit as they revolve with the sane speed as the rotating
flux , once the excitation is cut off , the relative motion
between flux and the copper bars come into action and the
motor starts operating as a induction motor.

Is This Answer Correct ?    27 Yes 16 No



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