GE MiCOM P40

= (100+30) x 0.484 Ð 79.4° x 0.12
= 7.56 Ð 79.4° W secondary
So:
●
Set Z2 Ph. Reach and Z2 Gnd. Reach = 7.56 W
● Set Z2 Ph. Angle and Z2 Gnd. Angle = 80°
Alternatively, in Simple setting mode, this reach can be set as a percentage of the protected line. Typically a
figure of at least 120% of the line between Green Valley and Blue River is used.
6.11.5 ZONE 3 PHASE AND GROUND REACH SETTINGS
For the protection at Green Valley:
In Advanced mode:
Required Zone 3 impedance = 1.2(line impedance of Green Valley to Blue River) + line impedance
from Blue River to Rocky Bay
= 1.2*(100+60) x 0.484
Ð 79.4° x 0.12
= 11.15
Ð 79.4° W secondary
So:
●
Set Z3 Ph. Reach and Z2 Gnd. Reach = 11.15 W
● Set Z2 Ph. Angle and Z2 Gnd. Angle = 80°
Alternatively, in Simple setting mode, this reach can be set as a percentage of the protected line.
6.11.6
ZONE 3 REVERSE REACH SETTINGS
For the protection at Green Valley:
In the absence of special requirements, because the protected line length is more than 30km, Zone 3 can be given
a small reverse reach – say 10%.
Using Advanced mode, in the DISTANCE SETUP column, set:
●
Z3' Ph Rev Reach and Z3' Gnd Rev Rch = 0.1*5.81 = 0.58 W
6.11.7
ZONE 4 REVERSE REACH SETTINGS
For the protection at Green Valley:
Where Zone 4 is used to provide reverse directional decisions for Blocking or Permissive Overreach schemes, Zone
4 must reach further behind the local protection than Zone 2 of the remote protection. This can be achieved by
setting Zone 4 ³ 1.2 x Remote Zone 2 reach, where mho characteristics are used.
Remote Zone 2 Reach = line impedance of Green Valley to Blue River + 50% line impedance from
Green valley to Tiger Bay
= (100 + 40) x 0.484 Ð 79.4° x 0.12
= 8.13
Ð 79.4° W secondary
Zone 4 Reach ³ (8.13 Ð 79.4° x 120%) - 5.81 Ð 79.4°
= 3.95
Ð 79.4° W secondary
Chapter 7 - Distance Protection P446SV
160 P446SV-TM-EN-1