GE D60 - Page 560

8-10 D60 Line Distance Protection System GE Multilin
8.1 DISTANCE ELEMENTS 8 THEORY OF OPERATION
8
I
A
 Z
L
+ I_0  K0  Z
L
+ I
G
 K0M  Z
L
– V
A
= 57.0 V 108.7°
I
A
 Z
L
+ I_0  K0  Z
L
= 45.8 V 82.9°
• Overcurrent supervision: | 3  I_0 | = 4.09 A  3 A
• Reactance difference angle = | –3.9° – 24.8° | = 28.7°  75°
• Zero-sequence difference angle = | –19.8° – 0.0° | = 19.8°  75°
• Negative-sequence directional difference angle = | –19.8° – 0.0° | = 19.8°  75°
• Right blinder difference angle = | –93.0° – (–109.2°) | = 16.2°  90°
• Left blinder difference angle = | 82.9° – 108.7° | = 25.8°  90°
• Fault-type comparator difference angle = | 19.8° – 19.8° | = 0.0°  50°
All six comparators and the overcurrent supervision are satisfied.
The Quad Phase A ground element will operate for this fault.