GE UR Series L90, Инструкция по эксплуатации

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GE Multilin L90 Line Current Differential System 9-27
9 THEORY OF OPERATION 9.3 DISTANCE ELEMENTS
9
Left Blinder RCA: 88°
Polarizing Current: Zero-sequence
Non-Homogeneity Correction Angle: 3°
Directional RCA: 88°
Z0/Z1 Magnitude: 4.55
Overcurrent supervision: 3 A
Z0/Z1 Angle: –12°
Distance Comparator limit angle: 75°
Z0M/Z1 Magnitude: 0
Directional Comparator limit angle: 75°
Assume the following signals are injected to the relay:
V
A
= 64.71 V

0.0° (pre-fault)
V
A
= 25.43 V

–19.9°
V
B
= 80.22 V

–133.5°
V
C
= 77.33 V

135.7°
I
A
= 4.47 A

–107.8°
I
B
= 2.92 A

68.9°
I
C
= 2.93 A

–51.1°
Based on the entered setting the relay calculates:
K0 = 3.58

–15.2°
K0M= 0
Z
= 14.00
 
88°
Z
D
= 1
 
88°
Z
R
= 9.99
 
2°
Z
L
= 4.99
 
178°
For the assumed steady-state injection the relay calculates:
V
A
_1 = 58.83 V

–2.1°
V
A
_1M = 64.71 V

0.0°
I_0 = 1.37 A

–68.2°
I
A
_2 = 1.37 A

–68.1°
–V_0 = 29.18 V

8.4°
(V
A
–V
B
)_1 = 93.35 V

32.0°
(V
A
–V
B
)_1M = 112.08 V

30.0°
I
A
–I
B
= 7.39 A

–109.1°
b) MHO PHASE A TO GROUND ELEMENT (BEFORE MEMORY EXPIRES)
I
A

Z + I_0

K0

Z + I
A

K0M

Z – V
A
= 103.33 V

–3.9°
V
A
_1M = 64.71 V

0.0°
I
A
_2

Z
D
= 1.37 V

19.8°
I_0

Z = 19.11 V

19.8°
I_0

Z
D
= 1.37 V

19.8°
• Overcurrent supervision: | 3

I_0 | = 4.09 A

3 A
• Mho difference angle = | –3.9° – 0° | = 3.9°

75°
• Reactance difference angle = | –3.9° – 19.8° | = 23.7°

75°
• Zero-sequence directional difference angle = | 19.8° – 0.0° | = 19.8°

75°
• Negative-sequence directional difference angle = | 19.8° – 0.0° | = 19.8°

75°
• Fault-type comparator difference angle = | 19.8° – 19.8° | = 0.0°

50°