• UNUnbalAlm> = 2.5% UBase
• UNUnbalWrn> = 1.0% UBase
• UMin> = 75% UBase
2. Activate the RESETCOMP input to ensure that the stored values of the compensation factors are
reset to zero.
3. The logical signals and service values for SCUVPTOV function are available on the local HMI
under: Main menu/Tests/Function status/Unbalance protection/
CapBankVoltageUnbalance(60V, Uub>)/SCUVPTOV(60V, Uub>):x, where x = instance number.
4. To store the new values of compensation factors, perform the following steps:
Step No. Changes after step 2 Expected Output
4-a Inject constant voltages* of U
L1
=
63.5∠0° V, U
L2
= 63.5∠240° V,
U
L3
= 63.5∠120° V,
and U
N
= 0∠0° V in secondary at
rated frequency.
UL1, UL2, and UL3 = 230.909 kV
UNSCB = 0.000 kV
UNUNBAL = 0.000 kV
PUNUNBAL= 0.000 %
The following outputs should show the mentioned
values:
• K1USED = 0.000
• K2USED = 0.000
• K1MON = 0.000
• K2MON = 0.000
4-b Change U
N
= 2∠0° V in
secondary at rated frequency
UL1, UL2, and UL3 = 230.909 kV
UNSCB = 7.273 kV
UNUNBAL = 7.273 kV
PUNUNBAL = 3.151 %
The following outputs should show the mentioned
values:
• K1USED = 0.000
• K2USED = 0.000
• K1MON = 0.030
• K2MON = 0.030
4-c Activate binary input TRIGCOMP
for 1 s
UL1, UL2, and UL3 = 230.909 kV
UNSCB = 7.273 kV
UNUNBAL = 0.000 kV
PUNUNBAL= 0.000 %
• The output COMPEXED should become
HIGH for 100 ms
• The output LASTCOMP should display the
date and time of compensation.
The following outputs should show the mentioned
values:
• K1USED = 0.030
• K2USED = 0.030
• K1MON = 0.030
• K2MON = 0.030
* - VT ratios of phase voltages and neutral voltages are considered as 400 kV/110 V. The value of
UBase is considered as 110 V.
The voltage inputs U
L1
, U
L2
, and U
L3
refer to the bus voltages and U
N
refers to the neutral voltage
input.
5. Check the respective operation of warning, alarm, and trip.
1MRK 504 165-UUS Rev. J Section 11
Testing functionality by secondary injection
Transformer protection RET670 227
Commissioning manual
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