ABB Relion 611 Series, Technical Manual

Page: 496 / 536

The phase-to-earth voltages are calculated from the phase-to-phase voltages when VT
connection is selected as "Delta" according to the equations.
U U U U
A AB CA = + −
( )
0
3
/
GUID-8581E9AC-389C-40C2-8952-3C076E74BDEC V1 EN
(Equation 61)
U U U U
B BC AB
= + −
( )
0
/ 3
GUID-9EB6302C-2DB8-482F-AAC3-BB3857C6F100 V1 EN
(Equation 62)
U U U U
C CA BC = + −
( )
0 / 3
GUID-67B3ACF2-D8F5-4829-B97C-7E2F3158BF8E V1 EN
(Equation 63)
If the
U
0
channel is not valid, it is assumed to be zero.
The phase-to-phase voltages are calculated from the phase-to-earth voltages when VT
connection is selected as "Wye" according to the equations.
U U U
AB A B
= −
GUID-674F05D1-414A-4F76-B196-88441B7820B8 V1 EN
(Equation 64)
U U U
BC B C
= −
GUID-9BA93C77-427D-4044-BD68-FEE4A3A2433E V1 EN
(Equation 65)
U U U
CA C A
= −
GUID-DDD0C1F0-6934-4FB4-9F79-702440125979 V1 EN
(Equation 66)
Section 9
1MRS757454 D
General function block features
490 611 series
Technical Manual