ABB REG670 Commissioning Manual page 274

Section 13
Testing functionality by secondary injection
268
10. Using the settings for VSet, VDeadband, C (Compensating factor) and Xr2
(transformer short circuit impedance) calculate the magnitude of Icc_i necessary
to cause a tap change command.
11. Inject current equal to I2Base for Transformer 1 and (I2Base - |Icc_i|) for
Transformer 2 so 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.
The voltage injection equal to VSet is required for both
transformers during this test.
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 OperationPAR is set to CC for each transformer in the parallel
group.
2. Confirm that OperCCBlock is set to Enable for each transformer in the parallel
group.
3. Review the setting for CircCurrLimit.
4. Review the setting for CircCurrBk to confirm whether a circulating current limit
will result in an Alarm state, Auto Block or Auto&Man Block of the automatic
voltage control for tap changer, for parallel control function TR8ATCC (90).
5. Inject a voltage V
B
6. Inject a load current for Transformer 1 that is equal to rated load current I2Base
and a load current for Transformer 2 that is 1% less than (I2Base – (I2Base ·
CircCurrLimit))
7. Confirm that the automatic voltage control for tap changer, for parallel control
function TR8ATCC (90) responds in accordance with the setting for CircCurrBk.
Alarm and blocking conditions can be confirmed through interrogation of the
event menu or the control menu on the local HMI.
VTmismatch during parallel operation
Generator protection REG670 2.2 ANSI and Injection equipment REX060, REX061, REX062
equal to VSet for each transformer.
1MRK 502 073-UUS A
SEMOD175185-841 v6
SEMOD175185-859 v4
Commissioning manual