GE P444

P
44x/EN AP/Hb6
Application Notes
(AP) 5
-14 MiCOM P40 Agile
P442, P444
V
α
N
= Z
1
.D
fault
.(I
α
+ k0.3I0) + R
fault
.I
fault
V
α
N
= Z
1
.D
fault
.(I
α
+
01
.3 0
3
ZZ
Ia I
−
+
+ R
fault
.I
fault
V
α
N
= (R
1
+j.X
1
).D
fault
.(I
α
+
(
)
( )
01 0 1
11
3.
RR X X
R jX
−+ −
−
.3I0) + R
fault
.I
fault
V
α
N
= (R
1
+j.X
1
).D
fault
.I
α
+
( )
01 0 1
3
R R jX X−+ −
.D
fault
.3I0 + R
fault
.I
fault
V
α
N
= R
1
.D
fault
.I
α
+
01
3
RR−
.D
fault
.3I0 + j.X1. D
fault
.I
α
+
( )
01
3
XX
j
−
.D
fault
.3I0 + R
fault
.I
fault
V
α
N
= R
1
.D
fault
.I
α
+
01
3
RR−
.D
fault
.3I0 + j.X1. D
fault
.I
α
+
( )
01
3
XX
j
−
.D
fault
.(I
A
+I
B
+I
C
) + R
fault
.I
fault
V
AN
= R
1
.D
fault
.I
A
+
01
3
RR−
.D
fault
.3I0 + .D
fault
.I
A
+
01
3
XX
j
−



.D
fault
.(I
B
+I
C
) + R
fault
.I
fault
V
AN
= R
1
.D
fault
.I
A
+
01
3
RR−
.D
fault
.3I0 +
01
2.
3
XX+



.D
fault
.
A
dl
dt
+
01
3
XX
+



.D
fault
.
dl
dt
B
+
01
3
XX+



.D
fault
.
dl
dt
C
+ R
fault
.I
fault
V
AN
= R
1
.D
fault
.I
A
+
01
3
RR
−
.D
fault
.3I0 + L
AA
.D
fault
.
A
dl
dt
+ L
AB
.D
fault
.
dl
dt
B
+ L
AC
.D
fault
.
dl
dt
C
+ R
fault
.I
fault
V
BN
= R
1
.D
fault
.I
B
+
01
3
RR−
.D
fault
.3I0 + L
AB
.D
fault
.
A
dl
dt
+ L
BB
.D
fault
.
dl
dt
B
+ L
BC
.D
fault
.
dl
dt
C
+ R
fault
.I
fault
V
CN
= R
1
.D
fault
.I
C
+
01
3
RR−
.D
fault
.3I0 + L
AC
.D
fault
.
A
dl
dt
+ L
BC
.D
fault
.
dl
dt
B
+ L
CC
.D
fault
.
dl
dt
C
+ R
fault
.I
fault
2.1.2 Impedance measurement algorithms work with instantaneous values (current and voltage).
The derived current value (dI/dt) is obtained by using a FIR filter.
2.1.3 Phase-to-phase loop impedance
P3032EN
R
Fault
V
C
Z
s
Z
s
Z
s
i
C
i
B
i
A
Z
1
Z
1
Z
1
V
CN
V
AN
Location
of Distance Relay
R / Phase
X / Phase
Z
Fault
Z
1
R
Fault
/ 2
V
BN
Figure 3: Phase-to-phase loop impedance