86 Practical examples
If only generator rating plate values are known, such rating plate values are needed that
are given when rotor is short-circuited. Power factor must be below 1. First magnetizing
current of the generator is calculated as shown below:
Mutual inductance X
m
and rotor resistance R
r
calculations
Mutual inductance X
m
(rotor-side converter parameter 99.24 XM) is calculated with the
following equation:
The rotor resistance R
r
(rotor-side converter parameter 99.25 Rr) reduced to the stator
reference frame (R2PH on the ABB generator equivalent circuit data) is calculated with the
following equation:
X1S and X2S are typically about 5% of the X
m
. R
s
and R
r
are typically about 0.5% of the
X
m
.
99.16 MOTOR NOM IM = 99.03 MOTOR NOM CURRENT· 1 - 99.12 MOTOR NOM COSFII
2
=
99.24 XM
99.02 MOTOR NOM VOLTAGE
· 99.16 MOTOR NOM IM
3
=
99.25 Rr
R2PH
2
99.15 MOTOR OPEN CKT V
99.02 MOTOR NOM VOLTAGE