ABB PQFA Instruction Manual page 41

T1
S1, k
P1, K
I1
S2, l
P2, L
P1 P2 P1 P2
S1 S2
I' 1-I' 0
k l
PQF 1
Figure 6.8. Two independent transformers: CT connection for one
For each phase, 3 CT' s must be installed:
Those CT' s must be identical: X/5 A.
CT I1 and CT I0 feed a summation CT which is connected to PQF1.
CT I2 and CT I0 feed a summation CT which is connected to PQF2.
Those summation CT' s must be 5+5 / 5 A.
Condition 1: the tie is open.
PQF1 sees I1 and PQF2 sees I2 (I0 = 0). The two transformers work
independently and the total current to be compensated is I1 + I2.
Condition 2: the tie is closed but both transformers feed the loads.
In this configuration, PQF1 sees (I1-I0) and PQF2 sees (I2+I0). The total
current seen by the two filters is I1 + I2.
I0
P1 P2
K
S1
S2
k l
phase.
Asea Brown Boveri Jumet S.A.
PQFA Instructions Manual
S1, k
P1, K
I2
S2, l
L
P2, L
P1 P2
S1 S2
k
PQF 2
- one to measure I1
- one to measure I2
- one to measure I0.
T2
P1 P2
I' 2+I' 0
l
41