ABB ACS800-67 - Mutual Inductance XM and Rotor Resistance Rr Calculations

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