P14x
5.2.2
FAULT TYPE DETECTOR LOGIC
V
NRMS
VN
RMS
FTD> VN
FTD> Fault Count
FTD> Time Window
Figure 142: Fault Type Detector Logic
5.2.3
DIRECTION DETECTOR LOGIC - STANDARD MODE
220 Hz
VN
Dir>Vnf Thresh
220 Hz
IN
Dir>Inf Thresh
V00907
Figure 143: Direction Detector Logic - Standard Mode
5.2.4
TRANSIENT EARTH FAULT DETECTION OUTPUT ALARM LOGIC
TEF Alarm Logic
TEF> Start
TEF> tRESET
Reset TEF
Figure 144: TEFD output alarm logic
P14xEd1-TM-EN-1
Average
-
Ʃ
low pass
filter
+
Sign filter
V
Add 90°
H1
phase shift
Sign filter
I
H2
t
0
1
Chapter 12 - Power Protection Functions
Pulse
Decision
Counter
ò
X
Note: In standard mode , Qtran comparison threshold is fixed at -0. 1 for the
forward direction and +0 .04 for the reverse direction.
&
&
Permanent
Intermittent
Disturbance
-0.1
Forward (faulty)
Q
tran
Reverse (healthy)
0.04
S
TEF Alarm Output
Q
R
V00906
V00909
273