GE Multilin
C70 Capacitor Bank Protection and Control System
9-15
9 APPLICATION OF SETTINGS
9.4 SETTING EXAMPLE
9
(EQ 9.13)
The voltage distribution factor for the healthy perfectly balanced bank for the 87V-2 and 87V-3 elements:
(EQ 9.14)
The impedance of the string for the failed capacitors elements (for one failed element,
n
f
= 1:
(EQ 9.15)
The voltage at the tap in the section with one failed capacitor element in the string:
(EQ 9.16)
The voltage of the top section with one capacitor element failed:
(EQ 9.17)
The overvoltage at the affected capacitors with one capacitor element failed:
(EQ 9.18)
The differential voltage between two taps with one failed capacitor element in the upper string, assuming
K
= 1 for 87V-1, in
per-unit values is:
(EQ 9.19)
The differential voltage between the bus voltage and the tap with one failed capacitor element in the upper string, assuming
K
= 1, for 87V-3 in per-unit values is:
(EQ 9.20)
The unbalance current in the window type CT between two strings with one failed capacitor element in the upper string:
(EQ 9.21)
The following table summarizes the calculated values for the number of failed capacitors used to set the protection ele-
ments.
V
bottom
V
max
Z
C
b
×
Z
C
t
--------------------------
81515.37 V 4.08
Ω
×
1894.92
Ω
--------------------------------------------------------
175.37 V
=
=
=
K
tap
V
top
V
bottom
-------------------
81340.40 V
175.37 V
-------------------------------
463.8194
=
=
=
Z
C
sf
Z
C
e
N n
×
n
f
–
(
)
Z
C
b
+
45.01
Ω
7 6
×
1
–
(
)
4.08
Ω
+
×
1849.41
Ω
=
=
=
V
tap
2
V
max
Z
C
b
×
Z
C
sf
--------------------------
81515.37 V 4.08
Ω
×
1849.91
Ω
--------------------------------------------------------
179.64 V
=
=
=
V
top
V
max
V
tap
2
–
=
OV
V
f top
(
)
N n
×
×
V
top
N n
×
n
f
–
(
)
×
-----------------------------------------------
81335.74 V 7
×
6
×
81340.40 V
7 6
×
1
–
(
)
×
----------------------------------------------------------------
1.024 pu
=
=
=
V
diff tap
(
)
V
tap
1
1
V
tap
2
×
–
VT
nom tap
(
)
-------------------------------------------
175.374 V 1 179.64 V
×
–
171.59 V
-------------------------------------------------------------------
0.0249 pu
=
=
=
V
diff string
(
)
V
f top
(
)
K
tap
V
tap
2
×
–
VT
nom bus
(
)
-----------------------------------------------------
175.374 V 463.8194 179.64 V
×
–
79674.34 V
-----------------------------------------------------------------------------------------
0.0249 pu
=
=
=
I
unbal
V
max
Z
C
sf
CT
tap
×
-----------------------------
V
max
Z
C
s
CT
tap
×
----------------------------
–
81515.37 V
1845.33
Ω
50
×
---------------------------------------
81515.37 V
1890.34
Ω
50
×
---------------------------------------
–
0.0209 pu
=
=
=
Содержание C70
Страница 10: ...x C70 Capacitor Bank Protection and Control System GE Multilin TABLE OF CONTENTS ...
Страница 30: ...1 20 C70 Capacitor Bank Protection and Control System GE Multilin 1 5 USING THE RELAY 1 GETTING STARTED 1 ...
Страница 394: ...5 270 C70 Capacitor Bank Protection and Control System GE Multilin 5 10 TESTING 5 SETTINGS 5 ...
Страница 452: ...8 18 C70 Capacitor Bank Protection and Control System GE Multilin 8 1 OVERVIEW 8 THEORY OF OPERATION 8 ...
Страница 474: ...9 22 C70 Capacitor Bank Protection and Control System GE Multilin 9 4 SETTING EXAMPLE 9 APPLICATION OF SETTINGS 9 ...
Страница 486: ...10 12 C70 Capacitor Bank Protection and Control System GE Multilin 10 6 DISPOSAL 10 MAINTENANCE 10 ...
Страница 630: ...B 110 C70 Capacitor Bank Protection and Control System GE Multilin B 4 MEMORY MAPPING APPENDIX B B ...
Страница 676: ...E 10 C70 Capacitor Bank Protection and Control System GE Multilin E 1 OVERVIEW APPENDIX E E ...
Страница 688: ...F 12 C70 Capacitor Bank Protection and Control System GE Multilin F 2 DNP POINT LISTS APPENDIX F F ...
Страница 698: ...H 8 C70 Capacitor Bank Protection and Control System GE Multilin H 3 WARRANTY APPENDIX H H ...