ABB RET650 Series Commissioning Manual page 85

1MRK 504 136-UUS B
Circulating current voltage regulation
This instruction for confirmation of circulating current voltage regulation assumes two
transformers in the parallel group. Setting confirmation through secondary injection requires
calculation of circulating currents for each transformer based on impedance values and respective
compensating factors, and is therefore more complex for greater than two transformers.
1. Confirm that
2. For parallel operation, it is also recommended that settings be confirmed for parallel group
membership, governed by setting
Setting/Control/TR8ATCC (90)/TR8ATCC:n/ParCtrl
The general parallel arrangement of transformers are defined by setting
or
If IED
•
•
T1 - T3 are available,
If
•
•
3. Review the settings for
calculate the upper (V2) and lower (V1) voltage regulation limits for which a tap change
command will be issued from the master transformer in the group.
4. Inject a voltage VB equal to
5. Inject a load current for Transformer 1 that is equal to rated load current
which is defined in a global base function, selected with setting
90) and a load current for Transformer 2 that is equal to 95% of rated load current
winding 2, which is defined in a global base function, selected with setting
for TR8ATCC (90)). This will have the effect of producing a calculated circulating current that
flows from HV to LV side for Transformer 1 and LV to HV side for Transformer 2.
6. Confirm that a circulating current is measured on the local HMI that is equal in magnitude to
5% of
GlobalBaseSel2 for TR8ATCC (90)), with polarity as discussed in step 5.
7. Confirm the settings for C
Impedance). Using these setting values and the measured quantity of circulating current
from the local HMI (I
Vdi
EQUATION2089-ANSI V1 EN-US
The voltage regulation algorithm then increases (for transformer
transformer
limits V1 and V2 for the purposes of voltage regulation.
Vi VB Vdi
EQUATION2091-ANSI V1 EN-US
Transformer protection RET650
Commissioning manual
OperationPAR is set to CC for the transformers in the parallel group.
Disabled . The following rules are applicable on the settings T1RXOP - T4RXOP .
T1 and T2 are connected,
T1RXOP shall be set to Enabled in instance 2 of TR8ATCC (90), and
T2RXOP shall be set to Enabled in instance 1 of TR8ATCC (90).
T1RXOP and T2RXOP shall be set to Enabled in instance 3 of TR8ATCC (90),
T2RXOP and T3RXOP shall be set to Enabled in instance 1 of TR8ATCC (90) and so on.
The parameter corresponding to the own IED must not be set.
thus not be set in IED
VDeadband (based on percentage of nominal bus voltage) and
IBase (for winding 2, which is defined in a global base function, selected with setting
i (Compensation Factor) and X i (Transformer Short Circuit
cc_i ), calculate the value for circulating current voltage adjustment V ci .
= × ×
Ci Icc i Xi _
T1 ) the measured voltage by Vdi and compares Vi against the voltage deadband
= +
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TnRXOP in the local HMI under Main menu/Setting/IED
T1 , T2RXOP not in IED T2 and so on.
VSet for each transformer.
Section 7
Testing functionality
SEMOD175185-775 v5
TnRXOP to Enabled
T1RXOP should
IBase (for winding 2,
GlobalBaseSel2 for TR8ATCC,
IBase (for
GlobalBaseSel2
(Equation 29)
T2 ) or decreases (for
(Equation 30)
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