Hi Everybody, I want to know about what does the meaning of Unbalance Load on the generator & how it causes the extra losses and results in temperature rise in the generator.

ALAM
[email protected]

 

Responding to ALAM's 18-Feb-07 (14;18) query:

Unbalanced loading of a generator's stator, produces different armature-reaction currents in each of the stator windings. The result is a reaction field that rotates at twice line frequency with respect to the rotor, thereby inducing a double-frequency current in the rotor. If appropriate action is not taken, the consequent current, referred to as the "negative-sequence" value, will lead to permanent generator damage. All generators can tolerate a certain level which can be graphed just as the time-current heating curve is produced for a motor.

Regards, Phil Corso, PE ([email protected])

 

Alam,

You have three different phases in the generator.
The output of these three phases may be connected to different loads. This results in different load (measured current) in the three phases. Also the relative phase angle (120 degree from each other) is affected. This is called Unbalanced load. The effect is same as in other replies.