ABB Relion 670 Series Applications Manual page 215

1MRK 511 401-UEN Rev. K
Groundlne
Impedance
IEC19000948 V1 EN-US
Figure 100: Possible CT and VT connections for the APPTEF function
The function shall measure the +3Io current with a reference direction towards the protected
line, as shown in
relevant CT inputs on the TRM from "ToObject", which is the default setting, to the value
"FromObject". This will enable the IED to turn around neutral current measurement and ensure
that the APPTEF function is looking in the right direction towards the protected line.
The +3Uo voltage shall be always connected to the IED as shown in
the measured residual voltage will always be performed internally by the function itself.
8.17.2.2 Global Base Value Settings
The parameter settings for the base quantities, which define the base value for pickup levels
of measuring stages are entered under global base values.
The base current shall be entered as the rated primary current of the CT to which the function
is connected.
The base voltage shall be entered as the rated phase-to-phase voltage of the protected line in
primary kV.
The APPTEF function will internally multiply this voltage set value with sqrt(3) before it will be
used. The reason is that the 3Uo "100% value" is sqrt(3) times bigger than the rated phase-to-
phase voltage for a high-impedance grounded system.
8.17.3 Settings guidelines
The parameters for the transient earth fault protection can be set using the local HMI or
PCM600. The following settings can be done for the APPTEF function.
Bay control REC670
Application manual
Power Trans-former
Ahernative VT
+3Uo
!
•
VT Input
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670 IED
Figure 100. If that is not the case, change the parameter
© Copyright 2017 Hitachi Power Grids. All rights reserved
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+31o
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- - - -
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Atternative CT
Connm;on,
Current protection
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l2
l3
CB
•
•
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•
,i
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IEC19000948-1-en.vsdx
CTStarPoint for the
Figure 100. The rotation of
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Section 8
209