CYG PRS-7367 - Page 18

Table of contents
10 PRS-7367
3.46.1 Overview ........................................................................................................................214
3.46.2 Differential Current Off Limit Alarm ................................................................................215
3.46.3 Instantaneous high stage principle ................................................................................215
3.46.4 Biased low stage principle .............................................................................................216
3.46.5 CT Supervision Block .....................................................................................................218
3.46.6 CT saturation blocking ...................................................................................................219
3.46.7 Overall Logic ..................................................................................................................219
3.46.8 Settings ..........................................................................................................................220
3.47 Flux-balance based differential protection 87MFDIF .............................. 221
3.47.1 Overview ........................................................................................................................221
3.47.2 Principle .........................................................................................................................222
3.47.3 Logic ...............................................................................................................................222
3.47.4 Settings ..........................................................................................................................222
3.48 Machine Startup MST ................................................................................. 223
3.48.1 Overview ........................................................................................................................223
3.48.2 Principle .........................................................................................................................223
3.48.3 Settings ..........................................................................................................................224
3.49 Long start protection MQDS ..................................................................... 225
3.49.1 Overview ........................................................................................................................225
3.49.2 Principle .........................................................................................................................225
3.49.3 Settings ..........................................................................................................................226
3.50 The locked-rotor protection MDZS ........................................................... 226
3.50.1 Overview ........................................................................................................................226
3.50.2 Principle .........................................................................................................................227
3.50.3 Settings ..........................................................................................................................227
3.51 Synchronous Motor Loss of Step 78O ..................................................... 228
3.51.1 Overview ........................................................................................................................228
3.51.2 Principle .........................................................................................................................228
3.51.3 Settings ..........................................................................................................................230
3.52 Synchronous Motor Loss of Excitation 40O ............................................ 231