Check The Overcurrent Block Function; Single Transformer - ABB REG670 Commissioning Manual

Section 13
Testing functionality by secondary injection
13.10.3.6
13.10.3.7
244

Check the overcurrent block function

1. Confirm the setting for Iblock in the local HMI under Main menu/Settings/
Setting group N/Control/TransformerVoltageControl(ATCC,91)/
TR1ATCC:x/TR8ATCC:x/TCCtrl/Iblock
2. Confirm the voltage control function response to an applied current above
Iblock, by reviewing the settings in the local HMI under Main menu/
Settings/General settings/Control/TransformerVoltageControl(ATCC,
91)/TR1ATCC:x/TR8ATCC:x/OVPartBk. This condition may cause an
alarm or total block of the voltage control function to be displayed on the
local HMI.
3. Inject a current higher than the Iblock setting and confirm the alarm or
blocking condition is present on the local HMI. If an automatic or total
blocking condition occurs, change the applied secondary voltage and confirm
that no tap change commands are issued from the associated binary outputs.
This situation can also be confirmed through reviewing the disturbance and
service reports on the local HMI.

Single transformer

Load drop compensation
1. Confirm that OperationLDC is set to On.
2. Confirm settings for Rline and Xline.
3. Calculate the expected load voltage U
local HMI) based on secondary injection of transformer secondary voltage
(U = USet) and rated load current (I
B
equation 110.
EQUATION2080 V3 EN-US
where:
U , I = Re(I ) + jlm(I
L L L L
When all secondary phase-to-earth voltages are available, use the positive-
sequence components of voltage and current. By separation of real and
imaginary parts:
= -
ul re ub re rline il re xline il im , ,
EQUATION2082 V1 EN-US
Generator protection REG670 2.2 IEC and Injection equipment REX060, REX061, REX062
(displayed as a measured value on the
L
= I1Base), in accordance with
L
) are complex phase quantities
× + ×
, ,
1MRK 502 073-UEN A
SEMOD175185-605 v5
SEMOD175185-669 v2
SEMOD175185-672 v5
(Equation 110)
(Equation 111)
Commissioning manual