ABB REG670 Applications Manual page 9

Generator protection REG670 2.2 IEC and Injection equipment REX060, REX061, REX062
Application manual
Setting guidelines...................................................................... 121
Section 7 Differential protection................................................... 127
Transformer differential protection T2WPDIF and T3WPDIF ........ 127
Identification.............................................................................. 127
Application................................................................................. 127
Setting guidelines...................................................................... 128
Restrained and unrestrained differential protection..............128
Elimination of zero sequence currents................................. 131
Inrush restraint methods.......................................................132
Overexcitation restraint method........................................... 132
Cross-blocking between phases.......................................... 133
External/Internal fault discriminator...................................... 133
On-line compensation for on-load tap-changer position.......135
Differential current alarm...................................................... 135
Open CT detection............................................................... 136
Switch onto fault feature.......................................................136
Setting example.........................................................................136
Introduction...........................................................................136
Typical main CT connections for transformer differential
protection..............................................................................137
Application Examples........................................................... 139
Summary and conclusions................................................... 146
High impedance differential protection, single phase HZPDIF ...... 148
Identification.............................................................................. 148
Application................................................................................. 148
The basics of the high impedance principle......................... 150
Connection examples for high impedance differential
protection...................................................................................156
Connections for three-phase high impedance differential
protection..............................................................................156
Connections for 1Ph High impedance differential
protection HZPDIF................................................................157
Setting guidelines...................................................................... 158
Configuration........................................................................ 158
Settings of protection function.............................................. 159
T-feeder protection............................................................... 159
Tertiary reactor protection.................................................... 162
Restricted earth fault protection........................................... 165
Alarm level operation............................................................166
Generator differential protection GENPDIF ................................... 167
Identification.............................................................................. 167
Application................................................................................. 168
Setting guidelines...................................................................... 169
Table of contents
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