ABB RELION REG670 Commissioning Manual page 225

1MRK 502 067-UEN B
Icc i
EQUATION2098 V1 EN-US
10. Using the settings for
short circuit impedance) calculate the magnitude of Icc
change command.
11. Inject current equal to
that the magnitude of calculated circulating current will cause a raise command to be
issued for Transformer 2 and a lower command for Transformer 1. Magnitude and
direction of circulating currents measured for each transformer can be observed as
service values on the local HMI and raise/lower commands detected from the binary
output mapped in the Signal Matrix.
12. Confirm that a tap change command is issued from the voltage control function to
compensate for the circulating current.
13. Injected currents can be reversed such that the direction of calculated circulating
currents change polarity, which will cause a lower command for Transformer 2 and a raise
command for Transformer 1.
Circulating current limit
1. Confirm that
2. Confirm that
3. Review the setting for
4. Review the setting for
in an
changer, for parallel control function TR8ATCC.
5. Inject a voltage U
6. Inject a load current for Transformer 1 that is equal to rated load current
load current for Transformer 2 that is 1% less than (
7. Confirm that the automatic voltage control for tap changer, for parallel control function
TR8ATCC responds in accordance with the setting for
conditions can be confirmed through interrogation of the event menu or the control
menu on the local HMI.
VTmismatch during parallel operation
1. Confirm that
2. Review the setting for
3. Inject a voltage U
VTmismatch · USet )) for Transformer 2.
(
4. This condition should result in a
the automatic voltage control for tap changer, parallel control function TR8ATCC for all
transformers connected in the parallel group, which can be confirmed through
interrogation of the local HMI.
5. Confirm that the automatic voltage control for tap changer, parallel control function
TR8ATCC responds in accordance with the setting for
Commissioning manual
( )
-
U 2 Uset
>
_
(
Ci Xi
USet , UDeadband , C (Compensating factor) and Xr2 (transformer
I2Base for Transformer 1 and ( I2Base - |Icc_ i |) for Transformer 2 so
The voltage injection equal to
during this test.
OperationPAR is set to CC for each transformer in the parallel group.
OperCCBlock is set to On for each transformer in the parallel group.
CircCurrLimit .
CircCurrBk to confirm whether a circulating current limit will result
Alarm state, Auto Block or Auto&Man Block of the automatic voltage control for tap
USet for each transformer.
equal to
B
OperationPAR is set to MF for each transformer in the parallel group.
VTmismatch and tVTmismatch .
USet for Transformer 1 and a voltage less than ( USet –
equal to
B
)
×
USet is required for both transformers
I2Base – ( I2Base · CircCurrLimit))
VTmismatch which will mutually block the operation of
Testing functionality by secondary injection
_i necessary to cause a tap
I2Base and a
CircCurrBk . Alarm and blocking
CircCurrBk .
Section 12
(Equation 124)
SEMOD175185-841 v6
SEMOD175185-859 v4
219