GE MiCOM P143 Agile User Manual

For insulated earth applications, it is common to use the Isin characteristic.
All of the relev
ant settings can be found under the SEF PROTECTION column.
11.5.3 DIRECTIONAL SEF LOGIC
V00619
SEF Options
I2H Any Start
ISEF> Blocking
2H Blocks ISEF>1
Inhibit SEF
ISEF>1 Current
VTS Slow Block
ISEF> Blocking
VTS Blks ISEF>1
ISEF> VNpol Set
Directional
check
ISEF>1 Direction
ISEF> Char Angle
ISEF>1 Timer Blk
AR Blk Main Prot
ISEF>Blocking
AR Blks ISEF>3
PN> Setting
SEF Options
Wattmetric
ISEF>1 Start
ISEF>1 Trip
&
IDMT/DT
Timer Settings
&
&
&
&
&
&
AR blocking available for DT-only stages
Note: This diagram does not show all stages . Other stages follow
similar principles.
AR blocking is only available for stages 3 and 4
ISEF
ISEFsin(phi)
ISEFcos(phi)
VN.ISEF.cos phi
VN
Figure 64: Directional SEF with VN polarisation (single stage)
The sensitive ear
th fault protection can be set IN/OUT of service using the appropriate DDB inhibit signal, which
can be operated from an opto-input or control command. VT Supervision (VTS) selectively blocks the directional
protection or causes it to revert to non-directional operation. When selected to block the directional protection,
VTS blocking is applied to the directional checking which effectively blocks the start outputs as well.
The directional check criteria are given below for the standard directional sensitive earth fault element:
● Directional forward: -90° < (angle(IN) - angle(VN + 180°) - RCA) < 90°
● Directional reverse: -90° > (angle(IN) - angle(VN + 180°) - RCA) > 90°
Three possibilities exist for the type of protection element that you can use for sensitive earth fault detection:
● A suitably sensitive directional earth fault protection element having a characteristic angle setting (RCA) of
zero degrees, with the possibility of fine adjustment about this threshold.
● A sensitive directional zero sequence wattmetric protection element having a characteristic angle setting
(RCA) of zero degrees, with the possibility of fine adjustment about this threshold.
●
A sensitive directional earth fault protection element having Icosf and Isinf characteristics.
P14x Chapter 6 - Current Protection Functions
P14xEd1-TM-EN-1 135

GE MiCOM P143 Agile Specifications

General

Brand	GE
Model	MiCOM P143 Agile
Category	Control Unit
Language	English