Start-Up - ABB SPAU 341 C User Manual

Start-up

18
L
N
T1
M
Tx
U 12
Serial
port
Lower Raise
Parallel
I L1 (RSV)
Man' Auto'
SPAU 341 C
R1 Adr. 10/11
–
Man' Auto'
CB1
Fig. 11. Three voltage regulators type SPAU 341 C1 operating in parallel using the minimizing
circulating current principle. The parallel mode of operation of the regulators is automatically
selected when the transformers are connected in parallel. When one of the transformars is con-
nected for single operation, the concerned regulator also switches over to the same mode of opera-
tion (automatic/manual) it had before the parallel operation.
Before starting the regulator, take the following
precautions:
Check that the phasing of the measured voltage
and current is correct, and that the current to
be measured is properly selected using the soft-
ware switches. This is easily done by comparing
the phase shift measured by the module SPCU
1D50 with the actual phase shift of the network.
Check the connection of the raise and lower
outputs by switching the regulator to manual
mode and operating the tap-changer in any di-
rection.
If the TCO (tap-changer operating) input is
connected, check that the corresponding LED
on the front panel of module SPCN 1D56 is
lit during tap-changer operation. If the TCO
input is not connected, the setting of OPD (out-
put pulse duration) should be shorter than the
operate time of the tap-changer, but enough
close to it to prevent regulating pulses during
tap-changer operation.
It should be remembered that the setting values
of a regulator always are a compromise between
the amount of regulating pulses during a cer-
tain time and the stability of the regulated volt-
T2
M
Rx
U 12
Lower Raise
–
I L1
SPAU 341 C
Single/
R2 Adr. 20/21
Parallel
–
Man' Auto'
CB2
age. If the setting values are too sensitive, the
tap-changer is operated too often and unneces-
sary wear is caused. The setting values affecting
the sensitivity of the regulator are: ∆U
U
is only used in parallel operation.
The ∆Us setting value should be selected ac-
cording to the power transformer's step volt-
age, approximately as high as the step voltage,
relative to the nominal voltage. During start-
up the time delays T1 and T2 should be rather
long, for instance, 60 s and 30 s. If required,
the settings can be changed after start-up.
If parallel operation is used, the stability setting
value should be very small, for example, 10%,
when the operation is started. Check that the
transformers are equally loaded by reading the
phase shifts from the automatic voltage regu-
lating modules SPCU 1D50. When transform-
ers are connected in parallel, the phase shifts
should be equal or, practically, equal. By increas-
ing the stability setting value, the optimal regu-
lation is achived.
For additional information about the settings
see the manual of the automatic voltage regu-
lating module SPCU 1D50.
L
N
T3
M
Tx
Rx
U 12
Serial
port
–
Parallel
(RSV)
I L1
Man' Auto'
SPAU 341 C
Single/
R3 Adr. 30/31
Parallel
– –
Man' Auto'
CB3
, U and Stability. The stability setting value
r x
L
N
Tx
Rx
Serial
port
Lower Raise
–
Parallel
(RSV)
Man' Auto'
Single/
Parallel
– –
, T1, T2,
s