
3.2.3.1
EARTH FAULT REACTANCE LINES
Both forward and reverse reach reactance lines feature a fixed tilt. For the Impedance Reach line, the fixed tilt can
be set to reinforce underreaching or overreaching preferences for the zone. For the Reverse Impedance Reach line,
the fixed tilt is preset at -3º.
The tilting of the reactance lines can be set such that tilting will be affected by the choice of polarizing quantity. If
dynamic tilting is selected, the protection automatically chooses the best polarizing quantity from either the phase
current or negative sequence current. The choice depends on which line is being polarized and on the relationship
of measured currents I2 and Iph. When I2 is used as the polarizing quantity, the tilt can dynamically vary according
to the angle of I2. If Iph is used, the tilt remains fixed at the set angle.
Consider polarization of the reactance lines for the case of a phase-earth fault:
For a phase-earth fault:
V = Vph
and assuming that mutual compensation is not applied:
I = Iph + k
ZN
.IN.
To avoid overreaching or underreaching due to the voltage drop in the arc resistance, the top line of the
characteristic should be ideally tilted by an angle:
Ð
(I
fault
/ I)
So that the total angle of tilt should be:
Ð
(I
fault
/ I) +
σ
where I
fault
is the fault current and σ is the fixed tilt of the reactance line (user setting for the Impedance Reach
line, fixed -3º preset for the Reverse Impedance Reach line.
If Z is the zone reach setting then the reactance line is formed by phase comparison between an operating signal
V – I Z (S1), and a polarizing quantity, I
POL
(S2).
I
fault
should be used to determine S2, but, because the Distance protection cannot measure the fault current
directly (due to the unknown infeed from the remote end), I
fault
cannot be used as the polarizing current. Instead,
the angle of I
fault
must be estimated. Two proven methods to estimate the angle of I
fault
are:
1.
The angle of I
fault
can be assumed to be close to the angle of Iph
2.
The angle of I
fault
can be assumed to be close to the angle of the negative sequence current I2.
In case 1, the angle of Iph can be used to polarize the Quadrilateral characteristic and so the tilt of the reactance
line is fixed.
In case 2 the angle of I2 can be used to polarize the Quadrilateral characteristic. In this case, the reactance line tilt
varies dynamically according to the angle of I2.
The reactance line follows the fault resistance impedance and tilts up or down, starting from the set initial tilt angle
(σ) to avoid underreaching or overreaching.
For both fixed and dynamic tilting the validity of current polarization is controlled by the following condition:
|
Ð
I2 -
Ð
Iph | < 45º
If this condition is not fulfilled, the assumptions that the angle of I
fault
is close to the angle of Iph or close to the
angle of I2 cannot be considered valid. Under such conditions the Quadrilateral characteristic could significantly
overreach or underreach. To avoid this, the distance protection automatically switches from Quadrilateral to Mho
characteristics to provide stable operation.
P446SV
Chapter 7 - Distance Protection
P446SV-TM-EN-1
131
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 ...
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