ABB RELION 620 Series Technical Manual page 20

Table of contents
14
Operation principle............................................................... 508
Application............................................................................522
CT connections and transformation ratio correction.............537
Signals..................................................................................541
Settings................................................................................ 542
Monitored data..................................................................... 544
Technical data...................................................................... 546
Technical revision history..................................................... 547
Numerical stabilized low-impedance restricted earth-fault
protection LREFPNDF...............................................................547
Identification......................................................................... 547
Function block...................................................................... 547
Functionality......................................................................... 547
Operation principle............................................................... 548
Application............................................................................551
Signals..................................................................................556
Settings................................................................................ 557
Monitored data..................................................................... 557
Technical data...................................................................... 558
Technical revision history..................................................... 558
High-impedance based restricted earth-fault protection
HREFPDIF.................................................................................558
Identification......................................................................... 558
Function block...................................................................... 558
Functionality......................................................................... 559
Operation principle............................................................... 559
Application............................................................................560
The measuring configuration................................................563
Recommendations for current transformers ........................563
Setting examples..................................................................568
Signals..................................................................................571
Settings................................................................................ 572
Monitored data..................................................................... 572
Technical data...................................................................... 573
Technical revision history..................................................... 573
High-impedance differential protection HIxPDIF....................... 573
Identification......................................................................... 573
Function block...................................................................... 574
Functionality......................................................................... 574
Operation principle............................................................... 574
Application............................................................................576
Example calculations for busbar high-impedance
differential protection............................................................ 582
Signals..................................................................................585
620 series
Technical Manual