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Calculating X/R for AC generator
3

Calculating X/R for AC generator

Calculating X/R for AC generator

(OP)
All,

Using SKM, I'm trying to model an older EMD AC generator.  Its data sheet does not list X/R but does give me numerous other parameters:

AB21-6 Model
60Hz
900rpm
2190kW
2738kVA
0.8PF
600VAC Delta
2634A

xd   1.12
xq   0.67
xd'  0.28
xd"  0.19
x2   0.16
xo   ---

Tdo' 4.34
Td"  0.023
Td'  1.02
Ta   0.044

Does anyone know either a direct derivation or indirect estimation that would allow determination of X/R from the time constants?  Thanks much for any help!

RE: Calculating X/R for AC generator

You also need the armature resistance.  I suppose you could back your way into it through the time constants.

RE: Calculating X/R for AC generator

The although the term "armature" is most often used to describe the rotor of a DC machine, it may also be applied to an AC generator. The armature is the component that uses or develops the load current. The field is the component that induces the EMF in the armature. In an AC machine (generator) the armature may be either stationary or rotating. I have seen both arrangements with AC generators. The stationary armature (stator) is by far the most common.

Bill
--------------------
"Why not the best?"
Jimmy Carter

RE: Calculating X/R for AC generator

I think only Ta[dc component time constant] may be useful in order to calculate the stator resistance:
As Ta=x2[ohm]/2/pi()/frq/ra [sec]
ra=x2[ohm]/2/pi()/frq/Ta [ohm]
x2[ohm]=x2*U^/S
U=0.6 kV
S=2.738 MVA
frq=60
ra=0.001268 ohm
ra=stator [star] resistance
rdelta=3*ra
rdelta=3*0.001268=0.0038 ohm
 

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