Micom P634 - Page 12

3.22.4 Operating Modes .......................................................................................................................................3-144
3.22.5 Idiff>>> Threshold ....................................................................................................................................3-148
3.22.6 Applying Current Transformer Supervision ................................................................................................3-148
3.22.7 Measured Operating Data of Ground Differential Protection .....................................................................3-148
3.22.8 Protection of Autotransformers ................................................................................................................. 3-149
3.23 Definite-Time Overcurrent Protection (Function Groups DTOC1 to DTOC4) ............3-152
3.23.1 Enabling or Disabling DTOC Protection ......................................................................................................3-152
3.23.2 Phase Current Stages ................................................................................................................................3-154
3.23.3 Negative-Sequence Current Stages ...........................................................................................................3-156
3.23.4 Residual Current Stages ............................................................................................................................3-157
3.23.5 General Starting ........................................................................................................................................3-159
3.23.6 General Trip Signal ....................................................................................................................................3-159
3.23.7 Counters of the DTOC Protection Function ................................................................................................3-160
3.24 Inverse-time Overcurrent Protection (Function Groups IDMT1 to IDMT3) ............... 3-161
3.24.1 Enabling or Disabling IDMT Protection .......................................................................................................3-161
3.24.2 Time-Dependent Characteristics ............................................................................................................... 3-163
3.24.3 Phase Current Stage ..................................................................................................................................3-167
3.24.4 Negative-Sequence Current Stage ............................................................................................................ 3-168
3.24.5 Residual Current Stage ..............................................................................................................................3-170
3.24.6 Hold Time ..................................................................................................................................................3-171
3.24.7 General Starting ........................................................................................................................................3-172
3.24.8 Counters of the IDMT Protection Function .................................................................................................3-173
3.25 Thermal Overload Protection (Function Groups THRM1 and THRM2) ......................3-174
3.25.1 Enabling or Disabling Thermal Overload Protection .................................................................................. 3-174
3.25.2 Readiness of Thermal Overload Protection ................................................................................................3-174
3.25.3 Selection of Current ...................................................................................................................................3-176
3.25.4 Tripping Characteristics .............................................................................................................................3-177
3.25.5 Coolant Temperature Acquisition .............................................................................................................. 3-178
3.25.6 Warning Signal .......................................................................................................................................... 3-180
3.26 Time-Voltage Protection (Function Group V<>) ..................................................... 3-182
3.26.1 Disabling and Enabling V<> Protection .....................................................................................................3-182
3.26.2 V<> Protection Readiness .........................................................................................................................3-182
3.26.3 Voltage Monitoring .................................................................................................................................... 3-182
3.27 Over-/Underfrequency Protection (Function Group f<>) ........................................ 3-185
3.27.1 Disabling or Enabling Over‑/Underfrequency Protection ............................................................................3-185
3.27.2 Undervoltage Blocking and Evaluation Time .............................................................................................3-186
3.27.3 Operating Modes of Over-/Underfrequency Protection ..............................................................................3-186
3.27.4 Frequency Monitoring ................................................................................................................................3-186
3.27.5 Frequency Monitoring Combined with Differential Frequency Gradient Monitoring (df/dt) ........................3-186
3.27.6 Frequency Monitoring Combined with Mean Frequency Gradient Monitoring (Δf/Δt) ................................ 3-187
3.27.7 f
min
/f
max
Measurement ...............................................................................................................................3-189
3.28 Overfluxing Protection (Function Group V/f) ........................................................... 3-190
3.28.1 Enabling or Disabling Overfluxing Protection ............................................................................................ 3-190
3.28.2 Conditioning the Measured Value ..............................................................................................................3-190
3.28.3 Fixed-time Warning Stage .........................................................................................................................3-191
3.28.4 Fixed-time Tripping Stage ......................................................................................................................... 3-191
3.28.5 Variable-time Tripping Stage .....................................................................................................................3-191
3.29 Current Transformer Supervision (Function Group CTS) .........................................3-196
3.29.1 Enabling or Disabling the CTS Function .....................................................................................................3-196
3.29.2 Blocking CTS ..............................................................................................................................................3-196
3.29.3 Monitoring Condition ................................................................................................................................. 3-197
3.29.4 Signaling and Indication ............................................................................................................................3-199
3.29.5 Reset .........................................................................................................................................................3-200
3.29.6 Multiple Signaling from the CTS Function ..................................................................................................3-200
P634
Table of Contents
4 P634/EN M/R-42-A // P634‑311‑653