ABB rec670 Commissioning Manual page 171

1MRK 511 360-UEN A
Bay control REC670 2.1 IEC
Commissioning manual
Testing functionality by secondary injection
(Equation 42)
EQUATION2092 V2 EN
(Equation 43)
EQUATION2094 V2 EN
Therfore:
× ×
Ci Icc i Xi U _
EQUATION2096 V1 EN
(
-
U 2
>
Icc i _
EQUATION2098 V1 EN
10. Using the settings for USet, UDeadband, 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 USet 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 On for each transformer in the parallel
group.
3. Review the setting for CircCurrLimit.
(for the purposes of this test procedure)
> -
2 Uset
)
Uset
( )
×
Ci Xi
Section 10
(Equation 44)
(Equation 45)
165