Answer / krishan chand tyagi

Transfomer overfluxing can be result of
1. Overvoltage
2. Low system frequency
A transformer is designed to operate at or below a maximum
magnetic flux density in the transformer core. Above this
design limit the eddy current in the core and nearby
conductive components cause overheating which within a very
short time may cause severe damage.The magnetice flux in
the core is proportional to the voltage applied to the
winding divided by thhe impedence of the winding.The flux
in the core increase with either increasing voltage or
decreasing frequency.During starrtup or stardown of
generator connected transformers, o following a
loadrejection, the transformer may exeperience an excessive
ratio of volts to hertz, that is, become overexcited.

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