9-16
C70 Capacitor Bank Protection and Control System
GE Multilin
9.4 SETTING EXAMPLE
9 APPLICATION OF SETTINGS
9
To check the limits of protection sensitivity, the same calculations are repeated for the minimum system conditions, which
are considered to be 0.85 pu of nominal system voltage.
The minimum line to neutral system voltage is:
(EQ 9.22)
The following table summarizes the unbalance values during minimum system conditions.
The balance values during minimum operating conditions may be used to check sensitivity.
9.4.5 BANK VOLTAGE DIFFERENTIAL SETTINGS
The bank configuration, CT location, and VT locations allow applying three voltage differential elements:
•
An 87V-1 differential element measuring the differential voltage between the two bottom taps.
•
An 87V-2 differential element measuring the differential voltage between the upper capacitor string and bottom capaci-
tor can for string 1.
•
An 87V-3 differential element measuring the differential voltage between the upper capacitor string and bottom capaci-
tor can for string 2.
Table 9–1: UNBALANCE VALUES FOR MAXIMUM SYSTEM CONDITIONS
0
1894.42
Ω
1894.42
Ω
175.37 V
175.37 V
81340.00 V 1.000 pu
0.0000 pu
0.0000 pu
0.0000 pu
1
1894.42
Ω
1849.41
Ω
175.37 V
179.64 V
81335.73 V 1.024 pu
0.0249 pu
0.0249 pu
0.0209 pu
2
1894.42
Ω
1804.40
Ω
175.37 V
184.12 V
81331.25 V 1.050 pu
0.0510 pu
0.0510 pu
0.0429 pu
3
1894.42
Ω
1759.39
Ω
175.37 V
188.83 V
81326.54 V 1.077 pu
0.0785 pu
0.0785 pu
0.0660 pu
4
1894.42
Ω
1714.38
Ω
175.37 V
193.79 V
81321.58 V 1.105 pu
0.1074 pu
0.1074 pu
0.0904 pu
5
1894.42
Ω
1669.38
Ω
175.37 V
199.01 V
81316.36 V 1.135 pu
0.1379 pu
0.1379 pu
0.1160 pu
6
1894.42
Ω
1624.37
Ω
175.37 V
204.52 V
81310.85 V 1.167 pu
0.1701 pu
0.1701 pu
0.1431 pu
7
1894.42
Ω
1579.36
Ω
175.37 V
210.35 V
81305.02 V 1.200 pu
0.2041 pu
0.2041 pu
0.1717 pu
8
1894.42
Ω
1534.35
Ω
175.37 V
216.52 V
81298.85 V 1.235 pu
0.2401 pu
0.2401 pu
0.2020 pu
9
1894.42
Ω
1489.34
Ω
175.37 V
223.07 V
81292.30 V 1.273 pu
0.2783 pu
0.2783 pu
0.2341 pu
10
1894.42
Ω
1444.34
Ω
175.37 V
230.02 V
81285.35 V 1.313 pu
0.3188 pu
0.3188 pu
0.2682 pu
Table 9–2: UNBALANCE VALUES FOR MINIMUM SYSTEM CONDITIONS
0
1894.42
Ω
1894.42
Ω
145.70 V
145.70 V
67577.30 V 1.000 pu
0.0000 pu
0.0000 pu
0.0000 pu
1
1894.42
Ω
1849.41
Ω
145.70 V
149.24 V
67573.76 V 1.024 pu
0.0207 pu
0.0207 pu
0.0174 pu
2
1894.42
Ω
1804.40
Ω
145.70 V
152.97 V
67570.03 V 1.050 pu
0.0424 pu
0.0424 pu
0.0357 pu
3
1894.42
Ω
1759.39
Ω
145.70 V
156.88 V
67566.12 V 1.077 pu
0.0652 pu
0.0652 pu
0.0549 pu
4
1894.42
Ω
1714.38
Ω
145.70 V
161.00 V
67562.00 V 1.105 pu
0.0893 pu
0.0893 pu
0.0751 pu
5
1894.42
Ω
1669.38
Ω
145.70 V
165.34 V
67557.66 V 1.135 pu
0.1146 pu
0.1146 pu
0.0964 pu
6
1894.42
Ω
1624.37
Ω
145.70 V
169.92 V
67553.08 V 1.167 pu
0.1413 pu
0.1413 pu
0.1189 pu
7
1894.42
Ω
1579.36
Ω
145.70 V
174.76 V
67548.24 V 1.200 pu
0.1696 pu
0.1696 pu
0.1426 pu
8
1894.42
Ω
1534.35
Ω
145.70 V
179.89 V
67543.11 V 1.235 pu
0.1995 pu
0.1995 pu
0.1678 pu
9
1894.42
Ω
1489.34
Ω
145.70 V
185.32 V
67537.68 V 1.273 pu
0.2312 pu
0.2312 pu
0.1945 pu
10
1894.42
Ω
1444.34
Ω
145.70 V
191.10 V
67531.90 V 1.313 pu
0.2649 pu
0.2649 pu
0.2228 pu
n
f
Z
C
s
Z
C
sf
V
tap
1
V
tap
2
V
top
OV
V
diff tap
(
)
V
diff string
(
)
I
unbal
V
min
0.85
V
nom
×
3
-------------------------------
0.85 138000 V
×
3
--------------------------------------------
67723 V
=
=
=
n
f
Z
C
s
Z
C
sf
V
tap
1
V
tap
2
V
top
OV
V
diff tap
(
)
V
diff string
(
)
I
unbal
Summary of Contents for C70
Page 10: ...x C70 Capacitor Bank Protection and Control System GE Multilin TABLE OF CONTENTS ...
Page 394: ...5 270 C70 Capacitor Bank Protection and Control System GE Multilin 5 10 TESTING 5 SETTINGS 5 ...
Page 676: ...E 10 C70 Capacitor Bank Protection and Control System GE Multilin E 1 OVERVIEW APPENDIX E E ...
Page 698: ...H 8 C70 Capacitor Bank Protection and Control System GE Multilin H 3 WARRANTY APPENDIX H H ...