44
6
F
2
S
0
7
8
9
2.11.7 Frequency Element FRQ
GRT100 has two elements for trip or alarm. Each element operates either in overfrequency or
underfrequency.
2.11.8 Overexcitation Element V/F
The characteristic is based on the ratio of voltage to frequency. The alarm is definite time
delayed, while the tripping characteristic is either definite time or inverse time, as shown in
Figure 2.11.6.
sec
V/Hz
0
L
H
HT
TVFH
LT
(log T)
A
TVFA
H: High level (definite time tripping)
L: Low level (pick up level)
HT: Operating time at high level
LT: Operating time at low level
A: Alarm level
TVFH: Operating time at high level setting
TVFA: Alarm time
Figure 2.11.6 Characteristic of Overexcitation Element
The inverse time characteristic of V/F is expressed by the following equation.
t =
K
2
(V/F)
K
1
where,
t : operating time
V : voltage (any phase-to-phase voltage)
F : frequency
V/F=(Vm/Fm) / (Vs/Fs)
(Vm: Input voltage, Fm: Input frequency, Vs: Setting of rated voltage, Fs: Rated frequency)
K
1
=
(LT)
L
(HT)
H
(LT)
(HT)
K
2
=
(LT)
(HT)
(H
L)
(LT)
(HT)
The V/F element has a reset feature with definite time reset (RT). When the V/F falls below the
reset threshold, the integral state of the inverse time function is reset to the initial value after the
RT time.
Example: V/F=(Vin/Fin)/(V/Fs)=(130/50)/(100/50)=1.3, in case of Vin: Input voltage (130V),
Fin: Input frequency (50Hz), V: Rated voltage (100V), Fs: Rated frequency (50Hz)
Содержание GRT100 Series
Страница 55: ... 54 6 F 2 S 0 7 8 9 TRANSFORMER PROTECTION GRT100 Operation keys 101B 21 11 Figure 3 1 9 Front Panel ...
Страница 142: ... 141 6 F 2 S 0 7 8 9 Appendix A Block Diagram ...
Страница 144: ... 143 6 F 2 S 0 7 8 9 Appendix B Signal List ...
Страница 159: ... 158 6 F 2 S 0 7 8 9 ...
Страница 160: ... 159 6 F 2 S 0 7 8 9 Appendix C Variable Timer List ...
Страница 162: ... 161 6 F 2 S 0 7 8 9 Appendix D Binary Output Default Setting List ...
Страница 165: ... 164 6 F 2 S 0 7 8 9 ...
Страница 166: ... 165 6 F 2 S 0 7 8 9 Appendix E Details of Relay Menu and LCD and Button Operation ...
Страница 174: ... 173 6 F 2 S 0 7 8 9 Appendix F Case Outline Flush Mount Type Rack Mount Type ...
Страница 179: ... 178 6 F 2 S 0 7 8 9 ...
Страница 180: ... 179 6 F 2 S 0 7 8 9 Appendix G External Connections ...
Страница 185: ... 184 6 F 2 S 0 7 8 9 ...
Страница 200: ... 199 6 F 2 S 0 7 8 9 ...
Страница 201: ... 200 6 F 2 S 0 7 8 9 Appendix J Return Repair Form ...
Страница 205: ... 204 6 F 2 S 0 7 8 9 Customer Name Company Name Address Telephone No Facsimile No Signature ...
Страница 206: ... 205 6 F 2 S 0 7 8 9 ...
Страница 207: ... 206 6 F 2 S 0 7 8 9 Appendix K Technical Data ...
Страница 220: ... 219 6 F 2 S 0 7 8 9 ...
Страница 221: ... 220 6 F 2 S 0 7 8 9 Appendix M Symbols Used in Scheme Logic ...
Страница 224: ... 223 6 F 2 S 0 7 8 9 ...
Страница 225: ... 224 6 F 2 S 0 7 8 9 Appendix N Implementation of Thermal Model to IEC60255 8 ...
Страница 228: ... 227 6 F 2 S 0 7 8 9 ...
Страница 229: ... 228 6 F 2 S 0 7 8 9 Appendix O IEC60870 5 103 Interoperability and Troubleshooting ...
Страница 241: ... 240 6 F 2 S 0 7 8 9 Appendix P Modbus Interoperability ...
Страница 255: ... 254 6 F 2 S 0 7 8 9 ...
Страница 256: ... 255 6 F 2 S 0 7 8 9 Appendix Q Inverse Time Characteristics ...
Страница 259: ... 258 6 F 2 S 0 7 8 9 ...
Страница 260: ... 259 6 F 2 S 0 7 8 9 Appendix R Failed Module Tracing and Replacement ...
Страница 266: ... 265 6 F 2 S 0 7 8 9 Appendix S Ordering ...
Страница 269: ... 268 6 F 2 S 0 7 8 9 3 1 Oct 2 2017 Republished under spin off company ...
Страница 270: ......