ABB Relion 670 series - Page 360

K
Z Z
Z
N
set set
set
=
−
⋅
0 1
3 1
IECEQUATION15017 V1 EN-US
Z R FwPEZx j X FwPEZx
set
0 0 0= + ⋅
IECEQUATION15028 V1 EN-US
Z R FwPEZx j X FwPEZx
set
1 1 1= + ⋅
IECEQUATION15029 V1 EN-US (Equation 105)
where
Z set0
is the complex zero sequence impedance of the line in Ω/phase
Z set1 
is the complex positive sequence impedance of the line in Ω/
phase
R0FwPEZx is the zero sequence resistive reach of the line in Ω/phase for
phase-to-ground fault in zone direction for zone x (x=1-5, or RV)
X0FwPEZx is the zero sequence reactance reach of the line in Ω/phase for
phase-to-ground fault in zone direction for zone x (x=1-5, or RV)
R1FwPEZx is the positive sequence resistive reach of the line in Ω/phase
for phase-to-ground fault in zone direction for zone x (x=1-5, or
RV)
X1FwPEZx is the positive sequence reactance reach of the line in Ω/phase
for phase-to-ground fault in zone direction for zone x (x=1-5, or
RV)
For an earth fault in phase A, the angle β between the compensation voltage and the polarizing
voltage
Vpol
is,
β = − + ⋅ ⋅ −arg[ ( ) ] ( )V I I K Z V
A A N set pol
3 0 1 arg
ANSIEQUATION15021 V1 EN-US (Equation 106)
where
VA
is the phase voltage in faulty phase A
IA
is the phase current in faulty phase A
3I
0
is the zero-sequence current in faulty phase A
Z set1 
is the complex positive sequence impedance of the line in Ω/
phase for phase-to-ground fault in zone direction
Vpol
is the polarizing voltage in phase A
Section 7 1MRK 502 066-UUS B
Impedance protection
354
Technical manual