ABB REG670 Technical Manual page 9

Technical manual
Settings......................................................................................142
Monitored data...........................................................................143
Operation principle.................................................................... 143
Logic diagram.......................................................................144
Technical data........................................................................... 145
Generator differential protection GENPDIF ................................... 146
Identification.............................................................................. 146
Functionality.............................................................................. 146
Function block........................................................................... 147
Signals.......................................................................................147
Settings......................................................................................148
Monitored data...........................................................................150
Operation principle.................................................................... 150
Function calculation principles............................................. 151
Fundamental frequency differential currents........................ 151
Supplementary criteria......................................................... 156
Harmonic restrain................................................................. 159
Open CT detection feature................................................... 159
Cross-block logic scheme.................................................... 161
Technical data........................................................................... 164
Low impedance restricted earth fault protection REFPDIF ........... 165
Identification.............................................................................. 165
Functionality.............................................................................. 165
Function block........................................................................... 166
Signals.......................................................................................166
Settings......................................................................................167
Monitored data...........................................................................168
Operation principle.................................................................... 168
Fundamental principles of the restricted earth-fault
protection..............................................................................168
Restricted earth-fault protection, low impedance
differential protection............................................................ 170
Calculation of differential current and bias current............... 172
Detection of external earth faults..........................................173
Algorithm of the restricted earth-fault protection.................. 175
Technical data........................................................................... 175
Section 7 Impedance protection...................................................177
Full-scheme distance measuring, Mho characteristic ZMHPDIS .. 177
Identification.............................................................................. 177
Functionality.............................................................................. 177
Function block........................................................................... 178
Signals.......................................................................................178
Settings......................................................................................179
Table of contents
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