
This feature is called permissive trip reinforcement. It is designed to ensure that synchronous tripping occurs at all
protected terminals.
4.2.2
PERMISSIVE OVERREACH WEAK INFEED FEATURES
Special weak infeed logic (WI) can be used with the POR schemes. The Weak Infeed setting can be found in the
SCHEME LOGIC column. Weak Infeed can be set to
Echo
,
Echo and Trip
, or
Disabled
.
Weak Infeed Echo
For a POR scheme, a signal is normally sent only if the appropriate signal associated with the pick up of the
sending zone detects a fault. However, under some circumstances, the fault current infeed at one line end may be
so low that it is insufficient to operate any of the distance zones. In another scenario, if a circuit breaker at one of
the terminals is in an open state, the current infeed will be zero. These scenarios are termed Weak Infeed (WI)
conditions. Without special attention they could result in slow fault clearance at the terminal that is feeding the
fault current (called the ‘strong infeed’ terminal). This would typically result in tripping after the Zone 2 time delay
(tZ2). To avoid Zone 2 delayed tripping, a device subject to Weak Infeed conditions can be set to echo signals
received on the Channel Aided link back to the initiating IED without delay. This allows the devices at points of
strong infeed to permissively trip instantaneously.
The Weak Infeed Echo Send logic is:
●
No Distance Zone Operation has been detected, but a POR Aided signal has been received.
Weak Infeed Echo and Trip
The Weak infeed echo logic will produce an aided trip at a strong infeed terminal, but it does not produce a trip at
the weak infeed. Setting Weak Infeed to
Echo and Trip
allows tripping of the weak infeed circuit breaker of a
faulted line. Three undervoltage elements, Va<, Vb< and Vc< are used to detect the line fault at the weak infeed
terminal. This voltage check prevents tripping during spurious operations of the channel or during channel testing.
The Weak Infeed Echo and Trip logic is:
●
No Distance Zone Operation has been detected, but a POR signal has been received, AND a V< condition
exists.
Weak infeed tripping is time delayed according to the value set in the WI Trip Delay settingin the SCHEME LOGIC
column. Due to the use of phase segregated undervoltage elements, single-phase tripping can be enabled for WI
trips if required. If single-phase tripping is disabled, under Weak Infeed conditions, three-phase tripping will occur
after the WI Trip Delay time has expired.
4.3
PERMISSIVE SCHEME LOSS OF GUARD
This scheme is intended for use with frequency shift keyed (FSK) power line carrier (PLC) communications.
When the protected line is healthy, a guard frequency is sent between line ends to verify the channel is in service.
However, when a line fault occurs and a permissive trip signal must be sent over the line, the power line carrier
frequency is shifted to a different (trip) frequency. Therefore the distance function should receive either the guard
frequency or the trip frequency, but not both together. For certain fault types, the line fault can attenuate the PLC
signals so the permissive signal is lost and not received at the other line end. To overcome this problem, when the
guard is lost and no trip frequency is received, the protection opens a window of time during which the permissive
scheme logic acts as though a trip signal had been received. Two opto-isolated inputs need to be assigned: One is
for Channel Receive; The second is designated Loss of Guard (the inverse function to guard received).
The Loss of Guard logic is described in the table below:
System condition
Permissive channel
received
Loss of guard
Permissive
trip allowed
Alarm
generated
Healthy Line
No
No
No
No
Internal Line Fault
Yes
Yes
Yes
No
P446SV
Chapter 8 - Carrier Aided Schemes
P446SV-TM-EN-1
175
Содержание MiCOM P40 Agile
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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