CHAPTER 15: THEORY OF OPERATION
THE D90
Plus
DISTANCE ELEMENTS
D90
PLUS
LINE DISTANCE PROTECTION SYSTEM – INSTRUCTION MANUAL
639
Mho phase A to ground element analysis, before memory expires
Before the memory expires, the following values are calculated for the mho phase A to
ground distance element.
Eq. 72
The ground distance element checks for the following conditions for overcurrent
supervision and the difference angles.
Table 16: Mho phase A to ground element conditions
The results are shown in the following table.
Table 17: Mho phase A to ground element analysis
All the comparators and the overcurrent supervision are satisfied.
Mho phase A to ground element analysis, after memory expires
After memory expires, the D90
Plus
checks the actual positive sequence voltage and
compares it to 10% of the nominal voltage.
Eq. 73
Parameter
Condition
Overcurrent supervision
3 ×
I
_0 >
Supervision
Mho difference angle
|
∠
(
I
A
×
Z
+
I
_0 ×
K
0
×
Z
R
+
I
G
×
K
0
M
×
Z
–
V
A
) –
∠
(
V
A
_1M) | <
Comparator Limit
Reactance difference angle
|
∠
(
I
A
×
Z
+
I
_0 ×
K
0
×
Z
R
+
I
G
×
K
0
M
×
Z
–
V
A
) –
∠
(
I
_0 ×
Z
) | <
Comparator Limit
Zero-sequence directional
difference angle
|
∠
(
I
_0 ×
Z
D
) –
∠
(
V
A
_1M) | <
Directional Comparator Limit
Negative-sequence
directional difference angle
|
∠
(
I
A
_2 ×
Z
D
) –
∠
(
V
A
_1M) | <
Directional Comparator Limit
Fault type comparator
difference angle
|
∠
(
I
A
_2 ×
Z
D
) –
∠
(
I
_0 ×
Z
D
) | < 50°
Parameter
Calculation
Requirement
Condition met
Overcurrent supervision
3 × 1.377 A = 4.09 A
> 3 A
Yes
Mho difference angle
| –3.9° – 0° | = 3.9°
< 75°
Yes
Reactance difference angle
| –3.9° – 19.8° | = 23.7°
< 75°
Yes
Zero-sequence directional
difference angle
| 19.8° – 0.0° | = 19.8°
< 75°
Yes
Negative-sequence directional
difference angle
| 19.8° – 0.0° | = 19.8°
< 75°
Yes
Fault type comparator
difference angle
| 19.8° – 19.8° | = 0.0°
< 50°
Yes
,
$
î=,Bî î= î
î=² 9²
.
,
.
9
0
*
$
9
$
9
B0
,
$
î 9
B
=
'
,
î 9
B
=
,
î 9
B
=
'
9
$
9!î9
B
Содержание D90 Plus
Страница 10: ...x D90PLUS LINE DISTANCE PROTECTION SYSTEM INSTRUCTION MANUAL TABLE OF CONTENTS ...
Страница 438: ...428 D90PLUS LINE DISTANCE PROTECTION SYSTEM INSTRUCTION MANUAL PROTECTION FLEXANALOG PARAMETERS CHAPTER 7 PROTECTION ...
Страница 502: ...492 D90PLUS LINE DISTANCE PROTECTION SYSTEM INSTRUCTION MANUAL AUTOMATION FLEXANALOG PARAMETERS CHAPTER 8 AUTOMATION ...
Страница 626: ...616 D90PLUS LINE DISTANCE PROTECTION SYSTEM INSTRUCTION MANUAL ENERVISTA SECURITY MANAGEMENT SYSTEM CHAPTER 13 SECURITY ...
Страница 678: ...668 D90PLUS LINE DISTANCE PROTECTION SYSTEM INSTRUCTION MANUAL SINGLE POLE TRIPPING CHAPTER 15 THEORY OF OPERATION ...
Страница 684: ...674 D90PLUS LINE DISTANCE PROTECTION SYSTEM INSTRUCTION MANUAL DISPOSAL CHAPTER 16 MAINTENANCE ...
Страница 686: ...676 D90PLUS LINE DISTANCE PROTECTION SYSTEM INSTRUCTION MANUAL REVISION HISTORY CHAPTER 17 APPENDIX ...