
to split the system will always be valid even if the accurate system data and setting parameters cannot be
obtained.
The predictive setting options
Pred. OST Trip
and
Pred. & OST Trip
are recommended for systems
where Out-of-Step conditions could possibly occur, and where an early system split should minimise the phase
shift between generation sources. This should maximise the chances for the separated parts of the system to
stabilise as quickly as possible. Special care must be taken when these settings are used to ensure that the circuit
breakers at the different terminals do not open when the voltages at different ends are in anti-phase. This is
because most circuit breakers are not designed to break current at double the nominal voltage. Attempting to
break the current at double the nominal voltage could lead to flash-over and circuit breaker damage.
‘Predictive’ settings are designed to detect and trip for fast power oscillations. When predictive tripping is used
with a circuit breaker capable of operating in typically two-cycles, the two voltages angles may rapidly move in
opposite directions at the time of opening the circuit breaker. So, if you use the predictive settings you need to
apply settings that will ensure that the circuit breaker opening occurs well before the phase difference between
the different terminals approaches 180º. This means that accurate settings can only be determined by exhaustive
system studies.
The setting
Pred. & OST Trip
provides two stages of OST. If a power system oscillation is very fast, the
combination of ∆R (the difference between the Zone 5 and Zone 6 resistive reaches), and the Delta T settings, must
be set so that
Pred. OST Trip
operates. If the oscillation is slower, the condition for the predictive OST is not
met and so tripping is dictated by the OST condition being met. For the OST condition to be met, the resistive
component of the impedance must leave Zone 5 with opposite polarity compared with when it entered. If the
polarity is opposite when Zone 5 resets, OST will trip. If the polarity is the same when Zone 5 resets, OST will not
trip. This distinguishes between a slower non-recoverable oscillation and recoverable swings.
You should disable OST for applications on lines where unrecoverable power oscillations are not expected, or not
expected to be severe. This is likely to apply to strong interconnected systems operating with three-phase tripping.
4.4.1.1
DETERMINING THE LIMITS OF THE OST CHARACTERISTIC
The figure below shows the OST characteristic in conjunction with the system impedance, ZT, and particularly the
relationship with the resistive reach of the Zone 5 element.
V02763
Zone 6
Zone 5
Resistive forward (+R)
Resistive reverse (R’)
α
OST Z5
OST Z6
OST Z5'
OST Z6'
OST R6
OST R5
OST R5'
OST R6'
+jX
Z
S
Z
L
Z
R
Z
T
OST trip
Predictive OST trip
θ
Figure 129: OST setting determination for the positive sequence resistive component OST R5
Chapter 10 - Power Swing Functions
P446SV
244
P446SV-TM-EN-1
Summary of Contents for MiCOM P40 Agile
Page 2: ......
Page 24: ...Contents P446SV xxii P446SV TM EN 1 ...
Page 33: ...CHAPTER 1 INTRODUCTION ...
Page 34: ...Chapter 1 Introduction P446SV 2 P446SV TM EN 1 ...
Page 46: ...Chapter 1 Introduction P446SV 14 P446SV TM EN 1 ...
Page 47: ...CHAPTER 2 SAFETY INFORMATION ...
Page 48: ...Chapter 2 Safety Information P446SV 16 P446SV TM EN 1 ...
Page 60: ...Chapter 2 Safety Information P446SV 28 P446SV TM EN 1 ...
Page 61: ...CHAPTER 3 HARDWARE DESIGN ...
Page 62: ...Chapter 3 Hardware Design P446SV 30 P446SV TM EN 1 ...
Page 88: ...Chapter 3 Hardware Design P446SV 56 P446SV TM EN 1 ...
Page 89: ...CHAPTER 4 SOFTWARE DESIGN ...
Page 90: ...Chapter 4 Software Design P446SV 58 P446SV TM EN 1 ...
Page 101: ...CHAPTER 5 CONFIGURATION ...
Page 102: ...Chapter 5 Configuration P446SV 70 P446SV TM EN 1 ...
Page 124: ...Chapter 5 Configuration P446SV 92 P446SV TM EN 1 ...
Page 125: ...CHAPTER 6 SAMPLED VALUE OPERATION ...
Page 126: ...Chapter 6 Sampled Value Operation P446SV 94 P446SV TM EN 1 ...
Page 136: ...Chapter 6 Sampled Value Operation P446SV 104 P446SV TM EN 1 ...
Page 137: ...CHAPTER 7 DISTANCE PROTECTION ...
Page 138: ...Chapter 7 Distance Protection P446SV 106 P446SV TM EN 1 ...
Page 196: ...Chapter 7 Distance Protection P446SV 164 P446SV TM EN 1 ...
Page 197: ...CHAPTER 8 CARRIER AIDED SCHEMES ...
Page 198: ...Chapter 8 Carrier Aided Schemes P446SV 166 P446SV TM EN 1 ...
Page 240: ...Chapter 8 Carrier Aided Schemes P446SV 208 P446SV TM EN 1 ...
Page 241: ...CHAPTER 9 NON AIDED SCHEMES ...
Page 242: ...Chapter 9 Non Aided Schemes P446SV 210 P446SV TM EN 1 ...
Page 256: ...Chapter 9 Non Aided Schemes P446SV 224 P446SV TM EN 1 ...
Page 257: ...CHAPTER 10 POWER SWING FUNCTIONS ...
Page 258: ...Chapter 10 Power Swing Functions P446SV 226 P446SV TM EN 1 ...
Page 281: ...CHAPTER 11 AUTORECLOSE ...
Page 282: ...Chapter 11 Autoreclose P446SV 250 P446SV TM EN 1 ...
Page 376: ...Chapter 11 Autoreclose P446SV 344 P446SV TM EN 1 ...
Page 377: ...CHAPTER 12 CB FAIL PROTECTION ...
Page 378: ...Chapter 12 CB Fail Protection P446SV 346 P446SV TM EN 1 ...
Page 389: ...CHAPTER 13 CURRENT PROTECTION FUNCTIONS ...
Page 390: ...Chapter 13 Current Protection Functions P446SV 358 P446SV TM EN 1 ...
Page 416: ...Chapter 13 Current Protection Functions P446SV 384 P446SV TM EN 1 ...
Page 417: ...CHAPTER 14 VOLTAGE PROTECTION FUNCTIONS ...
Page 418: ...Chapter 14 Voltage Protection Functions P446SV 386 P446SV TM EN 1 ...
Page 431: ...CHAPTER 15 FREQUENCY PROTECTION FUNCTIONS ...
Page 432: ...Chapter 15 Frequency Protection Functions P446SV 400 P446SV TM EN 1 ...
Page 438: ...Chapter 15 Frequency Protection Functions P446SV 406 P446SV TM EN 1 ...
Page 439: ...CHAPTER 16 MONITORING AND CONTROL ...
Page 440: ...Chapter 16 Monitoring and Control P446SV 408 P446SV TM EN 1 ...
Page 476: ...Chapter 16 Monitoring and Control P446SV 444 P446SV TM EN 1 ...
Page 477: ...CHAPTER 17 SUPERVISION ...
Page 478: ...Chapter 17 Supervision P446SV 446 P446SV TM EN 1 ...
Page 490: ...Chapter 17 Supervision P446SV 458 P446SV TM EN 1 ...
Page 491: ...CHAPTER 18 DIGITAL I O AND PSL CONFIGURATION ...
Page 492: ...Chapter 18 Digital I O and PSL Configuration P446SV 460 P446SV TM EN 1 ...
Page 504: ...Chapter 18 Digital I O and PSL Configuration P446SV 472 P446SV TM EN 1 ...
Page 505: ...CHAPTER 19 FIBRE TELEPROTECTION ...
Page 506: ...Chapter 19 Fibre Teleprotection P446SV 474 P446SV TM EN 1 ...
Page 522: ...Chapter 19 Fibre Teleprotection P446SV 490 P446SV TM EN 1 ...
Page 523: ...CHAPTER 20 ELECTRICAL TELEPROTECTION ...
Page 524: ...Chapter 20 Electrical Teleprotection P446SV 492 P446SV TM EN 1 ...
Page 534: ...Chapter 20 Electrical Teleprotection P446SV 502 P446SV TM EN 1 ...
Page 535: ...CHAPTER 21 COMMUNICATIONS ...
Page 536: ...Chapter 21 Communications P446SV 504 P446SV TM EN 1 ...
Page 606: ...Chapter 21 Communications P446SV 574 P446SV TM EN 1 ...
Page 607: ...CHAPTER 22 CYBER SECURITY ...
Page 608: ...Chapter 22 Cyber Security P446SV 576 P446SV TM EN 1 ...
Page 625: ...CHAPTER 23 INSTALLATION ...
Page 626: ...Chapter 23 Installation P446SV 594 P446SV TM EN 1 ...
Page 637: ...CHAPTER 24 COMMISSIONING INSTRUCTIONS ...
Page 638: ...Chapter 24 Commissioning Instructions P446SV 606 P446SV TM EN 1 ...
Page 695: ...CHAPTER 25 MAINTENANCE AND TROUBLESHOOTING ...
Page 696: ...Chapter 25 Maintenance and Troubleshooting P446SV 664 P446SV TM EN 1 ...
Page 712: ...Chapter 25 Maintenance and Troubleshooting P446SV 680 P446SV TM EN 1 ...
Page 713: ...CHAPTER 26 TECHNICAL SPECIFICATIONS ...
Page 714: ...Chapter 26 Technical Specifications P446SV 682 P446SV TM EN 1 ...
Page 741: ...APPENDIX A ORDERING OPTIONS ...
Page 742: ...Appendix A Ordering Options P446SV P446SV TM EN 1 ...
Page 744: ...Appendix A Ordering Options P446SV A2 P446SV TM EN 1 ...
Page 745: ...APPENDIX B SETTINGS AND SIGNALS ...
Page 746: ...Appendix B Settings and Signals P446SV P446SV TM EN 1 ...
Page 954: ...Appendix B Settings and Signals P446SV B208 P446SV TM EN 1 ...
Page 955: ...APPENDIX C WIRING DIAGRAMS ...
Page 956: ...Appendix C Wiring Diagrams P446SV P446SV TM EN 1 ...
Page 960: ......
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