European Network of Transmission System Operators for Electricity BUSBAR PROTECTION - BUSBAR DIFFERENTIAL: BEST PRACTICE AND RECOMMENDATIONS 04 December 2019 Page I ENTSO-E • Avenue de Cortenbergh, 100 • 1000 Brussels • Belgium • Tel +32 2 741 09 50 • Fax + 32 2 741 09 51• [email protected] • www.entsoe.eu European Network of Transmission System Operators for Electricity Table of contents page DEFINITIONS .................................................................................................................................. IV ABBREVIATIONS .............................................................................................................................. IV EXECUTIVE SUMMARY ........................................................................................................................ V LIST OF FIGURES ............................................................................................................................. VII 1 INTRODUCTION .................................................................................................................1 2 BUS BAR PROTECTION: PRINCIPLE OF OPERATION ...........................................................................1 FUNDAMENTALS ..................................................................................................................................................... 1 NUMERIC CURRENT DIFFERENTIAL, HIGH IMPEDANCE, STABILIZED, ETC. ............................................................................... 5 ARC PROTECTION (LIGHT SENSITIVE) ............................................................................................................................ 6 BUSBAR PROTECTION BLOCKING SCHEME SUPERVISION OR BLOCKING CRITERIA...................................................................... 7 BUSBAR SPLITTING ................................................................................................................................................... 8 DISTANCE PROTECTION ........................................................................................................................................... 11 ADDITIONAL TRIPPING CRITERIA FOR BBP DIFFERENTIAL ................................................................................................ 11 2.7.1 CHECK ZONE ...................................................................................................................................................... 11 2.7.2 CURRENT DIRECTION ........................................................................................................................................... 11 2.7.3 PHASE UNDER-VOLTAGE RELEASE CRITERION ............................................................................................................ 12 2.7.4 VOLTAGE SEQUENCE COMPONENTS RELEASE CRITERION .............................................................................................. 12 2.7.5 NEUTRAL OVER VOLTAGE RELEASE CRITERION ........................................................................................................... 12 2.7.6 NEUTRAL OVER CURRENT RELEASE CRITERION ........................................................................................................... 13 2.7.7 OVERCURRENT RELEASE OF THE TRIP COMMAND ....................................................................................................... 13 2.7.8 OTHER TRIPPING CRITERIA .................................................................................................................................... 13 3 BUSBAR DIFFERENTIAL PROTECTION CONFIGURATION ..................................................... 14 CENTRALIZED ARRANGEMENT ................................................................................................................................... 14 DECENTRALIZED ARRANGEMENT ............................................................................................................................... 14 4 SPECIAL BUSBAR ARRANGEMENTS/ COMPONENTS AND THEIR PROTECTION ..................... 15 THE ‘END FAULT’ PROTECTION ................................................................................................................................. 15 4.1.1 DEAD ZONE (BLIND SPOT) - A FAULT BETWEEN A CIRCUIT BREAKER AND A CURRENT TRANSFORMER ..................................... 15 4.1.2 A FAULT IN A BUS COUPLER OR A SWITCHED BUSBAR .................................................................................................. 16 ON-LOAD BUSBAR CHANGEOVER .............................................................................................................................. 17 BUS COUPLER TIME DELAY ...................................................................................................................................... 17 POLICY FOR ISOLATOR ALARM OR AUXILIARY CONTACT................................................................................................... 17 5 CIRCUIT BREAKER FAILURE PROTECTION (BFP) OPERATING PRINCIPLES ............................. 17 CONTINGENCY ARRANGEMENT IN CASE OF FAILURE OF BBP ............................................................................................ 18 DIRECT AND SELECTIVE TRIPPING .............................................................................................................................. 19 6 PRINCIPLES OF SETTING/PARAMETERIZATION FOR BBP AND BFP ........................................ 20 BBP SETTINGS AND COORDINATION FOR 1 ½ CONFIGURATION ....................................................................................... 22 7 ASSET MANAGEMENT ISSUES .................................................................................................. 23 BUSBAR PROTECTION INSPECTION ............................................................................................................................. 23 BUSBAR PROTECTION TESTING ................................................................................................................................. 23 REPLACEMENT OF BUSBAR PROTECTION ..................................................................................................................... 23 ADDITIONAL PROTECTION FUNCTIONS IN THE BUSBAR PROTECTION .................................................................................. 24 CERTIFICATION ..................................................................................................................................................... 24 FACTORY ACCEPTANCE TEST (FAT) ........................................................................................................................... 24 COMMISSIONING .................................................................................................................................................. 24 LIFE CYCLE ........................................................................................................................................................... 24 Page II ENTSO-E • Avenue de Cortenbergh, 100 • 1000 Brussels • Belgium • Tel +32 2 741 09 50 • Fax + 32 2 741 09 51• [email protected] • www.ENTSO-E.eu European Network of Transmission System Operators for Electricity 8 REFERENCE OF STANDARDS CIGRE AND RELATED TECHNICAL BROCHURES ......................................... 24 9 EVENTS / MALOPERATIONS / CASE STUDIES ............................................................................... 25 CEPS’S EVENT ...................................................................................................................................................... 25 10 TSO’S QUESTIONNAIRE .................................................................................................... 27 Q.1 [QUESTION 1] SUBSTATION DESIGN ISSUES .................................................................................................. 27 Q2 DIFFERENTIAL BBP BASED POLICY ............................................................................................................... 28 Q3. BUSBAR PROTECTION CONFIGURATION .................................................................................................. 31 Q4. BUSBAR PROTECTION OPERATING PRINIPLES (DIFFERENTIAL ETC.) ........................................................... 33 10.4.1 Q4.1. ADDITIONAL TRIPPING CRITERIA FOR BBP DIFFERENTIAL .................................................................... 34 Q5. SPECIAL BBP ARRANGMENTS/COMPONENTS ............................................................................................ 35 10.5.1 Q5.1. A FAULT IN A BAY BETWEEN A CB AND A CT.................................................................................................... 35 10.5.2 Q5.2. A FAULT IN BUS COUPLER BETWEEN CB AND CT .............................................................................................. 36 10.5.3 Q5.3. BUS COUPLER ........................................................................................................................................... 36 10.5.4 Q5.4. 1 1/2 BREAKER CONFIGURATION SUBSTATIONS ............................................................................................. 37 10.5.5 Q5.5. SPECIAL PROTECTION SCHEMES SUPPORTING BBP OPERATION ............................................................................ 37 10.5.6 Q5.6. ISOLATOR ALARM OR AUXILIARY CONTACT ...................................................................................................... 37 Q6. CIRCUIT BREAKER FAILURE PROTECTION OPERATING PRINCIPLES.