EQUATION2092 V2 EN
(Equation 42)
EQUATION2094 V2 EN
(Equation 43)
(for the purposes of this test procedure)
Therfore:
_
2
Ci Icc i Xi U
Uset
×
×
>
-
EQUATION2096 V1 EN
(Equation 44)
(
)
(
)
2
_
U
Uset
Icc i
Ci Xi
-
>
×
EQUATION2098 V1 EN
(Equation 45)
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
.
1MRK 511 360-UEN A
Section 10
Testing functionality by secondary injection
Bay control REC670 2.1 IEC
165
Commissioning manual