
9
SYSTEM CHECKS
In some situations it is possible for both "bus" and "line" sides of a circuit breaker to be live when a circuit breaker is
open - for example at the ends of a feeder that has a power source at each end. Therefore, it is normally necessary
to check that the network conditions on both sides are suitable, before closing the circuit breaker. This applies to
both manual circuit breaker closing and autoreclosing. If a circuit breaker is closed when the line and bus voltages
are both live, with a large phase angle, frequency or magnitude difference between them, the system could be
subjected to an unacceptable shock, resulting in loss of stability, and possible damage to connected machines.
The System Checks functionality involves monitoring the voltages on both sides of a circuit breaker, and if both
sides are live, performing a synchronisation check to determine whether any differences in voltage magnitude,
phase angle or frequency are within permitted limits.
The pre-closing system conditions for a given circuit breaker depend on the system configuration, and for
autoreclosing, on the selected autoreclose program. For example, on a feeder with delayed autoreclosing, the
circuit breakers at the two line ends are normally arranged to close at different times. The first line end to close
usually has a live bus and a dead line immediately before reclosing. The second line end circuit breaker now sees a
live bus and a live line.
If there is a parallel connection between the ends of the tripped feeder the frequencies will be the same, but any
increased impedance could cause the phase angle between the two voltages to increase. Therefore just before
closing the second circuit breaker, it may be necessary to perform a synchronisation check, to ensure that the
phase angle between the two voltages has not increased to a level that would cause unacceptable shock to the
system when the circuit breaker closes.
If there are no parallel interconnections between the ends of the tripped feeder, the two systems could lose
synchronism altogether and the frequency at one end could "slip" relative to the other end. In this situation, the
second line end would require a synchronism check comprising both phase angle and slip frequency checks.
If the second line-end busbar has no power source other than the feeder that has tripped; the circuit breaker will
see a live line and dead bus assuming the first circuit breaker has re-closed. When the second line end circuit
breaker closes the bus will charge from the live line (dead bus charge).
9.1
SYSTEM CHECKS IMPLEMENTATION
The System Checks function provides Live/Dead Voltage Monitoring, two stages of Check Synchronisation and
System Split indication.
The System Checks function is enabled or disabled by the System Checks setting in the CONFIGURATION column. If
System Checks is disabled, the SYSTEM CHECKS menu becomes invisible, and a SysChks Inactive DDB signal is
set.
The system Checks functionality can also be enabled or disabled individually for each circuit breaker by the
System Checks CB1 and System Checks CB2 settings in the SYSTEM CHECKS column. For the Systems Checks
functionality to be enabled, both the System Checks setting in the CONFIGURATION column AND the relevant
setting (System Checks CB1 and/or System Checks CB2) in the SYSTEM CHECKS column must be enabled. For the
System Checks functionality to be disabled, either the System Checks setting in the CONFIGURATION column OR
the relevant setting (System Checks CB1 and/or System Checks CB2) in the SYSTEM CHECKS column must be be
enabled. In the latter case, the SysChks Inactive DDB signal is set.
9.1.1
VT CONNECTIONS
The device provides inputs for a three-phase "Main VT" and at least one single-phase VT for check synchronisation.
Depending on the primary system arrangement, the Main VT may be located on either the line-side of the busbar-
side of the circuit breaker, with the Check Sync VT on the other. Normally, the Main VT is located on the line-side (as
per the default setting), but this is not always the case. For this reason, a setting is provided where you can define
this. This is the Main VT Location setting, which is found in the CT AND VT RATIOS column.
Chapter 16 - Monitoring and Control
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Страница 2: ......
Страница 24: ...Contents P446SV xxii P446SV TM EN 1 ...
Страница 33: ...CHAPTER 1 INTRODUCTION ...
Страница 34: ...Chapter 1 Introduction P446SV 2 P446SV TM EN 1 ...
Страница 46: ...Chapter 1 Introduction P446SV 14 P446SV TM EN 1 ...
Страница 47: ...CHAPTER 2 SAFETY INFORMATION ...
Страница 48: ...Chapter 2 Safety Information P446SV 16 P446SV TM EN 1 ...
Страница 60: ...Chapter 2 Safety Information P446SV 28 P446SV TM EN 1 ...
Страница 61: ...CHAPTER 3 HARDWARE DESIGN ...
Страница 62: ...Chapter 3 Hardware Design P446SV 30 P446SV TM EN 1 ...
Страница 88: ...Chapter 3 Hardware Design P446SV 56 P446SV TM EN 1 ...
Страница 89: ...CHAPTER 4 SOFTWARE DESIGN ...
Страница 90: ...Chapter 4 Software Design P446SV 58 P446SV TM EN 1 ...
Страница 101: ...CHAPTER 5 CONFIGURATION ...
Страница 102: ...Chapter 5 Configuration P446SV 70 P446SV TM EN 1 ...
Страница 124: ...Chapter 5 Configuration P446SV 92 P446SV TM EN 1 ...
Страница 125: ...CHAPTER 6 SAMPLED VALUE OPERATION ...
Страница 126: ...Chapter 6 Sampled Value Operation P446SV 94 P446SV TM EN 1 ...
Страница 136: ...Chapter 6 Sampled Value Operation P446SV 104 P446SV TM EN 1 ...
Страница 137: ...CHAPTER 7 DISTANCE PROTECTION ...
Страница 138: ...Chapter 7 Distance Protection P446SV 106 P446SV TM EN 1 ...
Страница 196: ...Chapter 7 Distance Protection P446SV 164 P446SV TM EN 1 ...
Страница 197: ...CHAPTER 8 CARRIER AIDED SCHEMES ...
Страница 198: ...Chapter 8 Carrier Aided Schemes P446SV 166 P446SV TM EN 1 ...
Страница 240: ...Chapter 8 Carrier Aided Schemes P446SV 208 P446SV TM EN 1 ...
Страница 241: ...CHAPTER 9 NON AIDED SCHEMES ...
Страница 242: ...Chapter 9 Non Aided Schemes P446SV 210 P446SV TM EN 1 ...
Страница 256: ...Chapter 9 Non Aided Schemes P446SV 224 P446SV TM EN 1 ...
Страница 257: ...CHAPTER 10 POWER SWING FUNCTIONS ...
Страница 258: ...Chapter 10 Power Swing Functions P446SV 226 P446SV TM EN 1 ...
Страница 281: ...CHAPTER 11 AUTORECLOSE ...
Страница 282: ...Chapter 11 Autoreclose P446SV 250 P446SV TM EN 1 ...
Страница 376: ...Chapter 11 Autoreclose P446SV 344 P446SV TM EN 1 ...
Страница 377: ...CHAPTER 12 CB FAIL PROTECTION ...
Страница 378: ...Chapter 12 CB Fail Protection P446SV 346 P446SV TM EN 1 ...
Страница 389: ...CHAPTER 13 CURRENT PROTECTION FUNCTIONS ...
Страница 390: ...Chapter 13 Current Protection Functions P446SV 358 P446SV TM EN 1 ...
Страница 416: ...Chapter 13 Current Protection Functions P446SV 384 P446SV TM EN 1 ...
Страница 417: ...CHAPTER 14 VOLTAGE PROTECTION FUNCTIONS ...
Страница 418: ...Chapter 14 Voltage Protection Functions P446SV 386 P446SV TM EN 1 ...
Страница 431: ...CHAPTER 15 FREQUENCY PROTECTION FUNCTIONS ...
Страница 432: ...Chapter 15 Frequency Protection Functions P446SV 400 P446SV TM EN 1 ...
Страница 438: ...Chapter 15 Frequency Protection Functions P446SV 406 P446SV TM EN 1 ...
Страница 439: ...CHAPTER 16 MONITORING AND CONTROL ...
Страница 440: ...Chapter 16 Monitoring and Control P446SV 408 P446SV TM EN 1 ...
Страница 476: ...Chapter 16 Monitoring and Control P446SV 444 P446SV TM EN 1 ...
Страница 477: ...CHAPTER 17 SUPERVISION ...
Страница 478: ...Chapter 17 Supervision P446SV 446 P446SV TM EN 1 ...
Страница 490: ...Chapter 17 Supervision P446SV 458 P446SV TM EN 1 ...
Страница 491: ...CHAPTER 18 DIGITAL I O AND PSL CONFIGURATION ...
Страница 492: ...Chapter 18 Digital I O and PSL Configuration P446SV 460 P446SV TM EN 1 ...
Страница 504: ...Chapter 18 Digital I O and PSL Configuration P446SV 472 P446SV TM EN 1 ...
Страница 505: ...CHAPTER 19 FIBRE TELEPROTECTION ...
Страница 506: ...Chapter 19 Fibre Teleprotection P446SV 474 P446SV TM EN 1 ...
Страница 522: ...Chapter 19 Fibre Teleprotection P446SV 490 P446SV TM EN 1 ...
Страница 523: ...CHAPTER 20 ELECTRICAL TELEPROTECTION ...
Страница 524: ...Chapter 20 Electrical Teleprotection P446SV 492 P446SV TM EN 1 ...
Страница 534: ...Chapter 20 Electrical Teleprotection P446SV 502 P446SV TM EN 1 ...
Страница 535: ...CHAPTER 21 COMMUNICATIONS ...
Страница 536: ...Chapter 21 Communications P446SV 504 P446SV TM EN 1 ...
Страница 606: ...Chapter 21 Communications P446SV 574 P446SV TM EN 1 ...
Страница 607: ...CHAPTER 22 CYBER SECURITY ...
Страница 608: ...Chapter 22 Cyber Security P446SV 576 P446SV TM EN 1 ...
Страница 625: ...CHAPTER 23 INSTALLATION ...
Страница 626: ...Chapter 23 Installation P446SV 594 P446SV TM EN 1 ...
Страница 637: ...CHAPTER 24 COMMISSIONING INSTRUCTIONS ...
Страница 638: ...Chapter 24 Commissioning Instructions P446SV 606 P446SV TM EN 1 ...
Страница 695: ...CHAPTER 25 MAINTENANCE AND TROUBLESHOOTING ...
Страница 696: ...Chapter 25 Maintenance and Troubleshooting P446SV 664 P446SV TM EN 1 ...
Страница 712: ...Chapter 25 Maintenance and Troubleshooting P446SV 680 P446SV TM EN 1 ...
Страница 713: ...CHAPTER 26 TECHNICAL SPECIFICATIONS ...
Страница 714: ...Chapter 26 Technical Specifications P446SV 682 P446SV TM EN 1 ...
Страница 741: ...APPENDIX A ORDERING OPTIONS ...
Страница 742: ...Appendix A Ordering Options P446SV P446SV TM EN 1 ...
Страница 744: ...Appendix A Ordering Options P446SV A2 P446SV TM EN 1 ...
Страница 745: ...APPENDIX B SETTINGS AND SIGNALS ...
Страница 746: ...Appendix B Settings and Signals P446SV P446SV TM EN 1 ...
Страница 954: ...Appendix B Settings and Signals P446SV B208 P446SV TM EN 1 ...
Страница 955: ...APPENDIX C WIRING DIAGRAMS ...
Страница 956: ...Appendix C Wiring Diagrams P446SV P446SV TM EN 1 ...
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