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Small levels of residual voltage could be present under normal system conditions due to system imbalances, VT
inaccuracies, device tolerances etc. For this reason, the device includes a user settable threshold (IN> VNPol set),
which must be exceeded in order for the DEF function to become operational. The residual voltage measurement
provided in the MEASUREMENTS 1 column of the menu may assist in determining the required threshold setting
during the commissioning stage, as this will indicate the level of standing residual voltage present.
Note:
Residual voltage is nominally 180° out of phase with residual current. Consequently, the DEF elements are polarised from the
"-Vres" quantity. This 180° phase shift is automatically introduced within the device.
The directional criteria with residual voltage polarisation is given below:
●
Directional forward: -90° < (angle(IN) - angle(VN + 180°) - RCA) < 90°
●
Directional reverse : -90° > (angle(IN) - angle(VN + 180°) - RCA) > 90°
4.3.2
NEGATIVE SEQUENCE POLARISATION
In some applications, the use of residual voltage polarisation may be not possible to achieve, or at the very least,
problematic. For example, a suitable type of VT may be unavailable, or an HV/EHV parallel line application may
present problems with zero sequence mutual coupling.
In such situations, the problem may be solved by using Negative Phase Sequence (NPS) quantities for polarisation.
This method determines the fault direction by comparing the NPS voltage with the NPS current. The operating
quantity, however, is still residual current.
This can be used for both the derived and measured standard earth fault elements. It requires a suitable voltage
and current threshold to be set in cells IN> V2pol set and IN> I2pol set respectively.
Negative phase sequence polarising is not recommended for impedance earthed systems regardless of the type
of VT feeding the relay. This is due to the reduced earth fault current limiting the voltage drop across the negative
sequence source impedance to negligible levels. If this voltage is less than 0.5 volts the device will stop providing
directionalisation.
The directional criteria with negative sequence polarisation is given below:
●
Directional forward: -90° < (angle(I2) - angle(V2 + 180°) - RCA) < 90°
●
Directional reverse : -90° > (angle(I2) - angle(V2 + 180°) - RCA) > 90°
Chapter 9 - Current Protection Functions
P54A/B/C/E
204
P54xMED-TM-EN-1
Summary of Contents for P4A
Page 2: ......
Page 20: ...Contents P54A B C E xviii P54xMED TM EN 1 ...
Page 27: ...CHAPTER 1 INTRODUCTION ...
Page 28: ...Chapter 1 Introduction P54A B C E 2 P54xMED TM EN 1 ...
Page 38: ...Chapter 1 Introduction P54A B C E 12 P54xMED TM EN 1 ...
Page 39: ...CHAPTER 2 SAFETY INFORMATION ...
Page 40: ...Chapter 2 Safety Information P54A B C E 14 P54xMED TM EN 1 ...
Page 52: ...Chapter 2 Safety Information P54A B C E 26 P54xMED TM EN 1 ...
Page 53: ...CHAPTER 3 HARDWARE DESIGN ...
Page 54: ...Chapter 3 Hardware Design P54A B C E 28 P54xMED TM EN 1 ...
Page 86: ...Chapter 3 Hardware Design P54A B C E 60 P54xMED TM EN 1 ...
Page 87: ...CHAPTER 4 SOFTWARE DESIGN ...
Page 88: ...Chapter 4 Software Design P54A B C E 62 P54xMED TM EN 1 ...
Page 99: ...CHAPTER 5 CONFIGURATION ...
Page 100: ...Chapter 5 Configuration P54A B C E 74 P54xMED TM EN 1 ...
Page 120: ...Chapter 5 Configuration P54A B C E 94 P54xMED TM EN 1 ...
Page 121: ...CHAPTER 6 CURRENT DIFFERENTIAL PROTECTION ...
Page 122: ...Chapter 6 Current Differential Protection P54A B C E 96 P54xMED TM EN 1 ...
Page 149: ...CHAPTER 7 AUTORECLOSE ...
Page 150: ...Chapter 7 Autoreclose P54A B C E 124 P54xMED TM EN 1 ...
Page 207: ...CHAPTER 8 CB FAIL PROTECTION ...
Page 208: ...Chapter 8 CB Fail Protection P54A B C E 182 P54xMED TM EN 1 ...
Page 219: ...CHAPTER 9 CURRENT PROTECTION FUNCTIONS ...
Page 220: ...Chapter 9 Current Protection Functions P54A B C E 194 P54xMED TM EN 1 ...
Page 244: ...Chapter 9 Current Protection Functions P54A B C E 218 P54xMED TM EN 1 ...
Page 247: ...CHAPTER 10 VOLTAGE PROTECTION FUNCTIONS ...
Page 248: ...Chapter 10 Voltage Protection Functions P54A B C E 222 P54xMED TM EN 1 ...
Page 261: ...CHAPTER 11 FREQUENCY PROTECTION FUNCTIONS ...
Page 262: ...Chapter 11 Frequency Protection Functions P54A B C E 236 P54xMED TM EN 1 ...
Page 268: ...Chapter 11 Frequency Protection Functions P54A B C E 242 P54xMED TM EN 1 ...
Page 269: ...CHAPTER 12 MONITORING AND CONTROL ...
Page 270: ...Chapter 12 Monitoring and Control P54A B C E 244 P54xMED TM EN 1 ...
Page 300: ...Chapter 12 Monitoring and Control P54A B C E 274 P54xMED TM EN 1 ...
Page 301: ...CHAPTER 13 SUPERVISION ...
Page 302: ...Chapter 13 Supervision P54A B C E 276 P54xMED TM EN 1 ...
Page 312: ...Chapter 13 Supervision P54A B C E 286 P54xMED TM EN 1 ...
Page 323: ...CHAPTER 14 DIGITAL I O AND PSL CONFIGURATION ...
Page 324: ...Chapter 14 Digital I O and PSL Configuration P54A B C E 298 P54xMED TM EN 1 ...
Page 336: ...Chapter 14 Digital I O and PSL Configuration P54A B C E 310 P54xMED TM EN 1 ...
Page 337: ...CHAPTER 15 FIBRE TELEPROTECTION ...
Page 338: ...Chapter 15 Fibre Teleprotection P54A B C E 312 P54xMED TM EN 1 ...
Page 354: ...Chapter 15 Fibre Teleprotection P54A B C E 328 P54xMED TM EN 1 ...
Page 355: ...CHAPTER 16 ELECTRICAL TELEPROTECTION ...
Page 356: ...Chapter 16 Electrical Teleprotection P54A B C E 330 P54xMED TM EN 1 ...
Page 366: ...Chapter 16 Electrical Teleprotection P54A B C E 340 P54xMED TM EN 1 ...
Page 367: ...CHAPTER 17 COMMUNICATIONS ...
Page 368: ...Chapter 17 Communications P54A B C E 342 P54xMED TM EN 1 ...
Page 439: ...CHAPTER 18 CYBER SECURITY ...
Page 440: ...Chapter 18 Cyber Security P54A B C E 414 P54xMED TM EN 1 ...
Page 457: ...CHAPTER 19 INSTALLATION ...
Page 458: ...Chapter 19 Installation P54A B C E 432 P54xMED TM EN 1 ...
Page 471: ...CHAPTER 20 COMMISSIONING INSTRUCTIONS ...
Page 472: ...Chapter 20 Commissioning Instructions P54A B C E 446 P54xMED TM EN 1 ...
Page 513: ...CHAPTER 21 MAINTENANCE AND TROUBLESHOOTING ...
Page 514: ...Chapter 21 Maintenance and Troubleshooting P54A B C E 488 P54xMED TM EN 1 ...
Page 530: ...Chapter 21 Maintenance and Troubleshooting P54A B C E 504 P54xMED TM EN 1 ...
Page 531: ...CHAPTER 22 TECHNICAL SPECIFICATIONS ...
Page 532: ...Chapter 22 Technical Specifications P54A B C E 506 P54xMED TM EN 1 ...
Page 558: ...Chapter 22 Technical Specifications P54A B C E 532 P54xMED TM EN 1 ...
Page 559: ...APPENDIX A ORDERING OPTIONS ...
Page 560: ...Appendix A Ordering Options P54A B C E P54xMED TM EN 1 ...
Page 565: ...APPENDIX B SETTINGS AND SIGNALS ...
Page 566: ...Appendix B Settings and Signals P54A B C E P54xMED TM EN 1 ...
Page 790: ...Appendix B Settings and Signals P54A B C E B224 P54xMED TM EN 1 ...
Page 835: ...APPENDIX C WIRING DIAGRAMS ...
Page 836: ...Appendix C Wiring Diagrams P54A B C E P54xMED TM EN 1 ...
Page 849: ......