Unsymmetrical generator load.

[Audun]

Hi

What guidlines do you know regarding unsymmetrical threephase generator load.
My question relates to the following case:
480V diesel generator.
Load currents for phases are approx.
2000 A, 2800 A, 800 A

PF=0.8

What generator rating is recomended. I think there are som production standards regarding singlephase load that generator manufacturers should follow for a threephase gen.

Audun

 

[electricpete]

The concern as you are probably aware is heating of the generator rotor surface. The negative sequence component of the current travels in the reverse direction creating 120hz current which will concentrate in the surface of the rotor and create heating.

I think that there has been a previous post on the subject of standards. (I don't remember them).