ABB Relion 670 Series Applications Manual page 506

Section 17
Monitoring
6. Enter the settings for all three CT input channels used for the LV side CTs as shown in
62.
Table 63: LV side CTs input channels
Setting parameter
CTprim
CTsec
CTStarPoint
7. Enter the values for the general settings of the PTRSTHR (51TF) function as shown in
64.
Table 64: Through fault monitoring function general settings
Setting parameter
ConnTypeW1
ConnTypeW2
ClockNumberW2
ZSCurrCor
OLTCWinding
LowTapOLTC1
RatedTapOLTC1
HighTapOLTC1
StepSizeOLTC1
1) Zero-sequence current is removed by connecting main CTs in delta, so winding current with zero sequence
Summary and conclusions
The IED can be used for through fault monitoring of transformers with main CTs are either wye or
delta connected. However, the IED is designed with an assumption that all main CTs are wye
connected. The IED can be used in applications where the main CTs are delta connected. For such
applications, consider the following:
• The ratio for delta connected CTs shall be set √3 = 1.732 times smaller than the actual
individual phase CT ratio.
• The power transformer phase shift shall typically be set as Yy0 since the compensation for
power transformer the actual phase shift is provided by the external delta CT connection.
• The zero sequence current is removed by the main CT delta connections. Therefore, when wye
winding sides, the CTs are connected in delta the zero sequence current correction shall be
set to
500
current is not possible
Disabled in the IED.
© Copyright 2017 ABB. All rights reserved
Selected value for solution 1 (wye
connected CT)
500
5
ToObject
Select value for solution 1 (wye
connected CT)
WYE (Y)
WYE (Y)
0 [0 deg]
Disabled
Winding 1 (W1)
1
12
23
1.5%
1MRK 511 401-UUS F
Table
Selected value for solution 2 (delta
connected CT)
500
=
289
3
EQUATION1892 V1 EN-US
(To compensate for delta
connected CTs)
5
ToObject
Table
Selected value for solution 2 (delta
connected CT)
WYE (Y)
WYE (Y)
0 [0 deg]
1)
Disabled
Winding 1 (W1)
1
12
23
1.5%
GUID-CC53DA83-EBDA-407A-9FFB-153600B4B3D2 v1
Bay control REC670
Application manual