ABB Relion 670 Series Applications Manual page 213

1MRK 511 401-UEN Rev. K
9. Set
10. Set
11. Set
All other settings can be left at the default values.
8.16.3.3 Overcurrent protection with undervoltage seal-in
To obtain this functionality, the IED application configuration shall include a logic in
accordance to figure
voltages shall be connected to VRPVOC. Let us assume that, taking into account the
characteristic of the generator, the excitation system and the short circuit study, the following
settings are required:
• Start current of the overcurrent stage: 150% of generator rated current at rated generator
voltage;
• Start voltage of the undervoltage stage: 70% of generator rated voltage;
• Trip time: 3.0 s.
The overcurrent stage and the undervoltage stage shall be set in the following way:
1. Set
2. Set
UBase and IBase equal to the rated phase-to-phase voltage and the rated phase current of
the generator.
3. Set
4. Set
5. Set
6. Set
stage is constant, irrespective of the magnitude of the generator voltage.
7. Set
8. Set
9. Set
10. Set
undervoltage stage.
The other parameters may be left at their default value.
8.17 Average Power Transient Earth Fault Protection,
APPTEF
8.17.1 Identification
Table 29:
Function description
Average Power Transient
Earth Fault Protection
8.17.2 Application
The APPTEF function is a transient measuring directional earth-fault protection.
Determination of the earth fault direction is based on the short-term built-up transient at the
beginning of the earth fault. This transient is independent of the neutral point treatment, thus
this function can be used without any modification in all the types of high-impedance
grounded, resonant grounded or isolated power systems.
Bay control REC670
Application manual
VDepMode to Slope (default value).
VDepFact to the value 25% (default value).
UHighLimit to the value 100% (default value).
99 and, of course, the relevant three-phase generator currents and
Operation to On .
GlobalBaseSel to the right value in order to select the Global Base Values Group with
StartCurr to the value 150 %.
Characteristic to IEC Def. Time .
tDef_OC to 6000.00 s, if no trip of the overcurrent stage is required.
VDepFact to the value 100 % in order to ensure that the start value of the overcurrent
Operation_UV to On to activate the undervoltage stage.
StartVolt to the values 70 %.
tDef_UV to 3.0 s.
EnBlkLowV to Off (default value) to disable the cut-off level for low-voltage of the
IEC 61850 identification
APPTEF
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IEC 60617 identification
Io > → TEF
Section 8
Current protection
GUID-B58E1CD6-F9AE-4301-ABE7-90DBFC987D69 v6
GUID-505DB872-1C09-47DB-BAD4-2FBDF652FE9F v1
ANSI/IEEE C37.2 device
number
67NT
GUID-79426533-7B21-4AB3-8F95-2D7DE7E4F903 v1
207