ABB Relion 670 Series Commissioning Manual page 191

1MRK 511 403-UUS Rev. K
9. To cause a tap change, the calculated value for circulating current voltage adjustment must offset
the injected quantity for bus voltage V
setting VDeadband. Expressed by equation
Vdi V
EQUATION2093-ANSI V1 EN-US
VB Vset
EQUATION2095-ANSI V1 EN-US
Therfore:
Ci Icc i Xi V
EQUATION2097-ANSI V1 EN-US
Icc i
EQUATION2099-ANSI V1 EN-US
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.
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).
Bay control REC670
Commissioning manual
> -
2 VB
(Equation 48)
=
(Equation 49)
× × > -
_ 2
( )
-
V 2 Vset
>
_
(
Ci Xi
The voltage injection equal to VSet is required for both transformers during this
test.
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so that Vi is outside the voltage deadband created by
B
48 and equation 49.
(for the purposes of this test procedure)
Vset
)
×
Section 11
Testing functionality by secondary injection
(Equation 50)
(Equation 51)
SEMOD175185-841 v6
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