GE MiCOM P40

or
Ð (V - I.Z) £ Ð I. Ð σ
The resultant two signals provided to the comparator are:
S
1
= V - I.Z
S
2
= I.
Ð σ
Impedance on the tripping side of the Impedance Reach line is detected when the angle between S1 and S2 is less
than 0°.
3.2.2.2 PHASE FAULT REVERSE IMPEDANCE REACH LINE
The Reverse Impedance Reach line of the phase quadrilateral elements has a tilt that is fixed at -3° as shown in the
following diagram:
+R
+jX
V02723
+Z’
V / I - Z’
V / I
-3°
Figure 49: Reverse impedance reach line construction
For an Offset zone, Z’ is the settable reverse reach. For a directional zone Z’ is a fixed percentage (either 25% or
100%) of the forward reach (Z) in the opposite direction.
The signals provided to the comparator are:
S
1
= V - I.Z’
S
2
= I.
Ð -3°
Impedance on the tripping side of the Reverse Impedance Reach line is detected when the angle between S1 and
S2 is greater than 0°.
3.2.2.3 PHASE FAULT RESISTIVE REACH LINE
Refer to the following figure:
P446SV Chapter 7 - Distance Protection
P446SV-TM-EN-1 127