5-242
G60 Generator Protection System
GE Multilin
5.6 GROUPED ELEMENTS
5 SETTINGS
5
Figure 5–128: 100% STATOR GROUND APPLICATION EXAMPLE
We have the magnitude of neutral voltage
V
N
as:
(EQ 5.36)
and the magnitude of the neutral and zero-sequence voltages
as:
(EQ 5.37)
Therefore, under the normal conditions described above, we set the operating quantities as follows:
(EQ 5.38)
In actual practice, the |
V
N
| / |
V
N
+
V
0
| ratio may vary from 0.4 to 0.85 under normal conditions. The pickup and supervision
setpoints are determined by evaluating the operating quantities during a fault condition (refer to example 2 for details).
Example 2: Operating quantities for a fault at a fraction
k
from the neutral grounding point.
For analysis, consider the above figure and assume that
.
In this case, we have the magnitude of the neutral voltage at:
(EQ 5.39)
and the magnitude of the neutral and zero-sequence voltages
as:
830737A1.CDR
S
Vn
(3rd)
Va
(3rd)
Vb
(3rd)
Vc
(3rd)
Pickup
3rd)
(
)
rd
3
(
)
rd
3
(
0
<
+
V
V
V
n
n
and
Pickup
1
3rd)
(
)
rd
3
(
)
rd
3
(
0
0
-
>
+
V
V
V
n
and
n
Supervisio
3rd)
(
)
rd
3
(
0
>
+
V
V
n
Va Vb Vc
E3
E3
E3
Vn
k
3V
0
(3rd)
V
N
R E
3
×
R jX
c
–
------------------
10 5
×
5
j
5
–
----------------
V
10
1
j
–
----------
V
=
=
=
V
N
7.07 V
=
V
N
V
0
+
V
0
jX
c
–
E
3
×
R jX
c
–
------------------------
j
50
–
5
j
5
–
--------------
j
10
–
1
j
–
-----------
=
=
=
V
N
V
0
+
10
j
10
–
1
j
–
---------------------
=
V
N
V
0
+
10 pu
=
Pickup
V
N
V
N
V
0
+
-----------------------
>
7.07
10
-----------
0.707 pu
=
=
Supervision
V
N
V
0
+
<
10 pu
=
E
3
10 V
=
,
R
5
Ω
,
X
c
5
Ω
, and
k
0.15
=
=
=
V
N
k E
3
×
0.15 10
×
1.5
=
=
=
V
N
V
0
+
Содержание Multilin g60
Страница 10: ...x G60 Generator Protection System GE Multilin TABLE OF CONTENTS INDEX ...
Страница 32: ...1 22 G60 Generator Protection System GE Multilin 1 5 USING THE RELAY 1 GETTING STARTED 1 ...
Страница 130: ...3 68 G60 Generator Protection System GE Multilin 3 4 FIELD AND STATOR GROUND MODULES 3 HARDWARE 3 ...
Страница 160: ...4 30 G60 Generator Protection System GE Multilin 4 3 FACEPLATE INTERFACE 4 HUMAN INTERFACES 4 ...
Страница 486: ...5 326 G60 Generator Protection System GE Multilin 5 10 TESTING 5 SETTINGS 5 ...
Страница 518: ...6 32 G60 Generator Protection System GE Multilin 6 5 PRODUCT INFORMATION 6 ACTUAL VALUES 6 ...
Страница 532: ...7 14 G60 Generator Protection System GE Multilin 7 2 TARGETS 7 COMMANDS AND TARGETS 7 ...
Страница 538: ...8 6 G60 Generator Protection System GE Multilin 8 1 PHASE DISTANCE THROUGH POWER TRANSFORMERS 8 THEORY OF OPERATION 8 ...
Страница 748: ...D 10 G60 Generator Protection System GE Multilin D 1 IEC 60870 5 104 APPENDIX D D ...
Страница 760: ...E 12 G60 Generator Protection System GE Multilin E 2 DNP POINT LISTS APPENDIX E E ...