Figure 47: Five-Sided Polygon Formed By Quadrilateral Characteristic With Directional-Line - GE MiCOM P40 Technical Manual

Chapter 7 - Distance Protection
Directional Quadrilateral Limits
The implementation of Directional Quadrilaterals in this product produces Directional Zone characteristics that are
formed by the combination of five comparators. Each comparator produces a straight line on the complex
impedance plane. The lines produced are:
● Impedance Reach Line
Reverse Impedance Reach Line
●
Resistance Reach Line
●
Reverse Resistance Reach Line
●
Directional Line.
●
Each of the lines produced by the comparators defines a tripping limit: Impedance on one side of the line prevents
tripping whereas impedance on the other side of the line may, if the other comparators agree, allow tripping. For
example, impedance beyond the Impedance Reach Line will not allow tripping.
The combination of the comparator outputs produces a polygon shaped tripping region. The polygon may be
either 4-sided or 5-sided. The shape depends according to the settings that are applied by the five comparators
and how the Directional Line interacts with the reach lines (usually the Reverse Impedance Reach Line):
The Directional Line may completely mask a reach line. If that is the case, the polygon will be 4-sided
●
(quadrilateral).
If the Directional Line intersects a reach line, the polygon will be 5-sided.
●
Creation of a 5-sided polygon is illustrated in the following figure:
Directional Line
V02773
Figure 47: Five-sided polygon formed by Quadrilateral characteristic with Directional-Line intersection of
Reverse Impedance Reach Line
The applied settings will determine the intersection point. When the settings have been chosen, the following
values will affect the line intersection point:
Impedance Reach
●
Reverse Impedance Reach
●
Resistive Reach
●
124
jX
-R
-jX
Forward direction
Reverse direction
P446SV
R
P446SV-TM-EN-1