If the CT para mismatch alarm is asserted the protection is also blocked.
The phase current measured values of the windings of the protected object are always scaled by the relevant
matching factors. These are then available for further processing. Consequently, all threshold values and
measured values refer back to the relevant reference currents rather than to the transformer nominal currents or
the nominal currents of the device.
3.6
SETTING UP ZERO SEQUENCE FILTERING
There are two modes of operation for zero sequence filtering; simple and advanced. You set the operation mode
with the Set Mode setting in the DIFFPROTECTION column.
In simple mode, you cannot disable zero sequence filtering. It is automatically implemented for all earthed
windings. You can define whether a winding is earthed or not with the settings HV Grounding, LV Grounding and
TV Grounding in the SYSTEM CONFIG column. If a setting is set to
grounded
, zero sequence filtering will always
be implemented for that winding. If set to
Ungrounded
, it will not be implemented.
In advanced mode, you can enable or disable zero sequence filtering manually using the settings Zero seq filt HV,
Zero seq filt LV and Zero seq filt TV in the DIFF PROTECTION column.
3.7
TRIPPING CHARACTERISTICS
The differential and bias currents for each phase are calculated from the current variables after amplitude and
vector group matching.
The differential current is the vector sum of the CT current inputs as follows:
P
I
I
I
P
I
diff y
s y CT
s y CT
d
642
643
1
2
:
:
,
, ,
, ,
=
+
iiff y
s y CT
s y CT
s y CT
I
I
I
P
,
, ,
, ,
, ,
=
+
+
1
2
3
645 ::
,
, ,
, ,
, ,
I
I
I
I
diff y
s y CT
s y CT
s y CT
=
+
+
+
1
2
3
II
I
s y CT
s y CT
, ,
, ,
4
5
+
The bias current is defined as half of the scalar sum of the CT current inputs:
P
I
I
I
P
I
bias y
s y CT
s y CT
642
0 5
643
1
2
:
.
:
,
, ,
, ,
=
⋅
+
b
bias y
s y CT
s y CT
s y CT
I
I
I
,
, ,
, ,
, ,
.
=
⋅
+
+
0 5
1
2
3
=
⋅
+
+
P
I
I
I
I
bias y
s y CT
s y CT
s
645
0 5
1
2
:
.
,
, ,
, ,
,
yy CT
s y CT
s y CT
I
I
,
, ,
, ,
3
4
5
+
+
where:
●
y is the measured phase (A, B or C)
●
I
s
is the current after the amplitude and vector group are matched.
The tripping characteristic has two knees. The first knee is dependent on the settings of Is1 and K1. The second
knee is defined by the setting Is2. The lower slope provides stability for low external faults. The higher slope
provides stability for high through fault conditions, since transient differential currents may be present due to
current transformer saturation.
Chapter 6 - Transformer Differential Protection
P64x
110
P64x-TM-EN-1.3
Содержание P642
Страница 2: ......
Страница 18: ...Contents P64x xvi P64x TM EN 1 3 ...
Страница 24: ...Table of Figures P64x xxii P64x TM EN 1 3 ...
Страница 25: ...CHAPTER 1 INTRODUCTION ...
Страница 26: ...Chapter 1 Introduction P64x 2 P64x TM EN 1 3 ...
Страница 36: ...Chapter 1 Introduction P64x 12 P64x TM EN 1 3 ...
Страница 37: ...CHAPTER 2 SAFETY INFORMATION ...
Страница 38: ...Chapter 2 Safety Information P64x 14 P64x TM EN 1 3 ...
Страница 50: ...Chapter 2 Safety Information P64x 26 P64x TM EN 1 3 ...
Страница 51: ...CHAPTER 3 HARDWARE DESIGN ...
Страница 52: ...Chapter 3 Hardware Design P64x 28 P64x TM EN 1 3 ...
Страница 87: ...CHAPTER 4 SOFTWARE DESIGN ...
Страница 88: ...Chapter 4 Software Design P64x 64 P64x TM EN 1 3 ...
Страница 98: ...Chapter 4 Software Design P64x 74 P64x TM EN 1 3 ...
Страница 99: ...CHAPTER 5 CONFIGURATION ...
Страница 100: ...Chapter 5 Configuration P64x 76 P64x TM EN 1 3 ...
Страница 121: ...CHAPTER 6 TRANSFORMER DIFFERENTIAL PROTECTION ...
Страница 122: ...Chapter 6 Transformer Differential Protection P64x 98 P64x TM EN 1 3 ...
Страница 165: ...CHAPTER 7 TRANSFORMER CONDITION MONITORING ...
Страница 166: ...Chapter 7 Transformer Condition Monitoring P64x 142 P64x TM EN 1 3 ...
Страница 189: ...CHAPTER 8 RESTRICTED EARTH FAULT PROTECTION ...
Страница 190: ...Chapter 8 Restricted Earth Fault Protection P64x 166 P64x TM EN 1 3 ...
Страница 215: ...CHAPTER 9 CURRENT PROTECTION FUNCTIONS ...
Страница 216: ...Chapter 9 Current Protection Functions P64x 192 P64x TM EN 1 3 ...
Страница 249: ...CHAPTER 10 CB FAIL PROTECTION ...
Страница 250: ...Chapter 10 CB Fail Protection P64x 226 P64x TM EN 1 3 ...
Страница 259: ...CHAPTER 11 VOLTAGE PROTECTION FUNCTIONS ...
Страница 260: ...Chapter 11 Voltage Protection Functions P64x 236 P64x TM EN 1 3 ...
Страница 274: ...Chapter 11 Voltage Protection Functions P64x 250 P64x TM EN 1 3 ...
Страница 275: ...CHAPTER 12 FREQUENCY PROTECTION FUNCTIONS ...
Страница 276: ...Chapter 12 Frequency Protection Functions P64x 252 P64x TM EN 1 3 ...
Страница 286: ...Chapter 12 Frequency Protection Functions P64x 262 P64x TM EN 1 3 ...
Страница 287: ...CHAPTER 13 MONITORING AND CONTROL ...
Страница 288: ...Chapter 13 Monitoring and Control P64x 264 P64x TM EN 1 3 ...
Страница 306: ...Chapter 13 Monitoring and Control P64x 282 P64x TM EN 1 3 ...
Страница 307: ...CHAPTER 14 SUPERVISION ...
Страница 308: ...Chapter 14 Supervision P64x 284 P64x TM EN 1 3 ...
Страница 322: ...Chapter 14 Supervision P64x 298 P64x TM EN 1 3 ...
Страница 323: ...CHAPTER 15 DIGITAL I O AND PSL CONFIGURATION ...
Страница 324: ...Chapter 15 Digital I O and PSL Configuration P64x 300 P64x TM EN 1 3 ...
Страница 336: ...Chapter 15 Digital I O and PSL Configuration P64x 312 P64x TM EN 1 3 ...
Страница 337: ...CHAPTER 16 COMMUNICATIONS ...
Страница 338: ...Chapter 16 Communications P64x 314 P64x TM EN 1 3 ...
Страница 397: ...CHAPTER 17 CYBER SECURITY ...
Страница 398: ...Chapter 17 Cyber Security P64x 374 P64x TM EN 1 3 ...
Страница 415: ...CHAPTER 18 INSTALLATION ...
Страница 416: ...Chapter 18 Installation P64x 392 P64x TM EN 1 3 ...
Страница 429: ...5 2 CASE DIMENSIONS 60TE E01409 Figure 167 60TE case dimensions P64x Chapter 18 Installation P64x TM EN 1 3 405 ...
Страница 431: ...CHAPTER 19 COMMISSIONING INSTRUCTIONS ...
Страница 432: ...Chapter 19 Commissioning Instructions P64x 408 P64x TM EN 1 3 ...
Страница 454: ...V01505 Figure 173 Harmonic Restraint Test Plane Chapter 19 Commissioning Instructions P64x 430 P64x TM EN 1 3 ...
Страница 460: ...Chapter 19 Commissioning Instructions P64x 436 P64x TM EN 1 3 ...
Страница 461: ...CHAPTER 20 MAINTENANCE AND TROUBLESHOOTING ...
Страница 462: ...Chapter 20 Maintenance and Troubleshooting P64x 438 P64x TM EN 1 3 ...
Страница 477: ...CHAPTER 21 TECHNICAL SPECIFICATIONS ...
Страница 478: ...Chapter 21 Technical Specifications P64x 454 P64x TM EN 1 3 ...
Страница 507: ...APPENDIX A ORDERING OPTIONS ...
Страница 508: ...Appendix A Ordering Options P64x P64x TM EN 1 3 ...
Страница 512: ...Appendix A Ordering Options P64x A4 P64x TM EN 1 3 ...
Страница 513: ...APPENDIX B SETTINGS AND SIGNALS ...
Страница 515: ...APPENDIX C WIRING DIAGRAMS ...
Страница 516: ...Appendix C Wiring Diagrams P64x P64x TM EN 1 3 ...
Страница 590: ......
Страница 591: ......