ABB REG650 - Page 9

Instantaneous differential currents....................................... 102
Harmonic and waveform block criteria................................. 102
Switch onto fault feature.......................................................103
Logic diagram.......................................................................104
Technical data........................................................................... 109
Restricted earth-fault protection, low impedance REFPDIF .......... 109
Identification.............................................................................. 109
Functionality.............................................................................. 110
Function block........................................................................... 110
Signals.......................................................................................110
Settings......................................................................................111
Monitored data...........................................................................111
Operation principle.................................................................... 112
Fundamental principles of the restricted earth-fault
protection..............................................................................112
Operate and restrain characteristic...................................... 114
Calculation of differential current and bias current............... 115
Detection of external earth faults..........................................116
Algorithm of the restricted earth-fault protection.................. 117
Technical data........................................................................... 118
1Ph High impedance differential protection HZPDIF .....................118
Identification.............................................................................. 118
Introduction................................................................................119
Function block........................................................................... 119
Signals.......................................................................................119
Settings......................................................................................120
Monitored data...........................................................................120
Operation principle.................................................................... 120
Logic diagram.......................................................................120
Technical data........................................................................... 121
Generator differential protection GENPDIF ................................... 121
Identification.............................................................................. 121
Functionality.............................................................................. 122
Function block........................................................................... 123
Signals.......................................................................................123
Settings......................................................................................124
Operation principle.................................................................... 125
Function calculation principles............................................. 126
Fundamental frequency differential currents........................ 126
Supplementary criteria......................................................... 131
Harmonic restrain................................................................. 134
Cross-block logic scheme.................................................... 134
Simplified block diagrams.....................................................134
Table of contents
3
Technical manual