Answer / mayilsamy ranganathan

we well known that all the generating staions are
interconnected by Transmission line and it is known as
interconnected grid system.The grid system is made to share
the load among all the powerstaion generators.
In a typical grid system the frequency is maintained at
50HZ,it means the generating power and power requirement of
the load is same.Hence in powerstaions the frequency is
monitored continuesly to findout the load requirement,if
the frequency dips below 50HZ,means the generator shaft
power increase and we have to give more input to generator
to meetout the extra load put on the shaft.Hence the
frequency is the measures of load,it is not constant,it is
continueously changing depending on load, we are trying to
bring it constant by maintaining generated power= Load
requirement.

Answer / nithi

In the power system most of the loads are induction motor
(nearly about 60%).so,apply this question for induction
motor.

For rated voltage,

below rated freq.: speed variation,high intake
current,over heating,insulation failure,core
saturation,harmonics production.

above rated freq.:drastic reduction in torque
production,speed variation.
so,frequency should be maintained constant.

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