ABB SPAU 341 C - Page 16

16
M
M
Raise LowerRaiseLower
U
12
Rem/Loc (BLOCK)
-
R2
SPAU 341 C1
CB1
CB2
CB3
TR1
TR2
R1
SPAU 341 C1
TCO
TCO
U
12
TCO
I
L1
I
L2,
I
L3
I
L1
-
TCO
~
N
~
N
N N
+
L R R L
Remote/local
selector switches
Rem/Loc (BLOCK)
SGF1/3=1
SGF1/3=1
I
L2,
I
L3
SGF2/6=0
SGF2/7=0
SGF2/6=0
SGF2/7=0
Fig. 9.Voltage regulators SPAU 341 C1 in parallel operation using the negative reactance princi-
ple. Depending on the position of the Remote/local selector switches, the operation mode of the
regulators can be selected via remote control (serial link) or local control (push-buttons). The
phase currents I
L2
,I
L3
are measured on the primary side of the transformer mainly for overcurrent
blocking purposes, while the phase current I
L1
is measured on the secondary side for the parallel
operation.