When assigning the Terminal Address, you must use the following convention:
●
Terminals must be allocated a Terminal Address from the choice available (
A
-
F
).
●
Starting with Terminal Address
A
, you must sequentially assign addresses
B
,
C,
etc., for the terminals in the
scheme.
You do not have to associate a specific Terminal Address with a specific terminal number, but we strongly
recommend that you observe the convention:
●
Assign Terminal Address
A
to terminal 1,
●
Assign Terminal Address
B
to terminal 2,
●
For schemes with more than 2 terminals:
○
Assign Terminal Address
C
to terminal 3 (for schemes with up to 3 terminals),
○
Assign Terminal Address
D
to terminal 4 (for schemes with up to 4 terminals),
○
Assign Terminal Address
E
to terminal 5 (for schemes with up to 5 terminals),
○
Assign Terminal Address
F
to terminal 6 (for schemes with up to 6 terminals),
Besides the communications addresses, you need only to set the clock source for each channel using settings
Clock Source Ch1 and Clock Source Ch2. We strongly recommend that the default value of
Internal
is always
used.
9.6
SETTING UP THE PHASE DIFFERENTIAL CHARACTERISTIC
The biased phase current differential characteristic is defined by four protection settings. Each can be set
independently. This flexibility allows the characteristic to be set for particular sensitivity and current transformer
requirements. To simplify setting the protection, however, we strongly recommend three of the settings be fixed as:
●
Phase Is2 = 2.0 pu
●
Phase k1 = 30% (This provides stability for small CT mismatches, while ensuring good sensitivity to resistive
faults under heavy load conditions
●
Phase k2 = 150% (For 2 terminal applications to provides stability under heavy through fault current
conditions)
●
Phase k2 = 100% (For 3 terminal applications to provides stability under heavy through fault current
conditions)
These settings give a characteristic suitable for most applications so that only the Phase Is1 setting needs
changing from the default value.
Phase Is1 is the setting which determines the minimum pick-up of the phase current differential elements. This
value should be set to account for any mismatch between the current transformers at the different terminals, as
well the capacitive charging current if this is not compensated.
If capacitive charging current compensation is not used, the setting of Phase Is1 must be set above 2.5 times the
steady state charging current. Where charging current is low or negligible, the recommended setting of 0.2 pu
(factory default) should be applied.
If there is a mismatch between CTs at line ends, then the lowest primary CT rated current should be used as a
reference current for p.u. calculations (assuming that the load current cannot continuously exceed this value). This
means that the recommended settings Phase Is1 = 0.2 pu is equal to 0.2*(the lowest primary CT rated value). The
same consideration applies for other current settings such as Phase Is2.
9.7
SENSITIVITY UNDER HEAVY LOADS
The sensitivity of the phase current differential protection is governed by its settings and also the magnitude of
load current in the system. For a three-ended system, with devices LOCAL, REMOTE1, and REMOTE2, the following
applies:
|I
diff
| = |(Ī
LOCAL
+ Ī
REMOTE1
+ Ī
REMOTE2
)|
P54A/B/C/E
Chapter 6 - Current Differential Protection
P54xMED-TM-EN-1
119
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: ......