Seg HighTECH MRG3 - Default Chapter; Table of Contents

Manual MRG3 SEG Electronics GmbH
DOK-TD-MRG3, Rev. D 3
Inhalt
1. Overview and Application ........................................................................... 6
2. Features and Characteristics ...................................................................... 7
3. Design ........................................................................................................... 8
3.1 Connections ........................................................................................................................ 8
3.1.1 Connection Diagrams ...................................................................................................... 8
3.1.2 Analog input circuits ...................................................................................................... 13
3.1.3 Output relays ................................................................................................................. 13
3.1.4 Blocking input ................................................................................................................ 13
3.1.5 External reset input ....................................................................................................... 13
3.1.6 Serial interface .............................................................................................................. 13
3.1.7 Auxiliary voltage supply ................................................................................................. 13
3.1.8 Code plugs .................................................................................................................... 14
3.1.9 Low/high range of the digital inputs............................................................................... 16
3.2 Front plates ....................................................................................................................... 17
3.3 LEDs .................................................................................................................................. 20
4. Working Principle ...................................................................................... 21
4.1 Analog circuits ................................................................................................................... 21
4.2 Digital circuits .................................................................................................................... 21
4.3 Voltage supervision ........................................................................................................... 21
4.3.1 Selection of star or delta connection ............................................................................. 22
4.4 Principle of frequency supervision .................................................................................... 23
4.5 Mains decoupling .............................................................................................................. 24
4.5.1 Measuring of frequency gradients ................................................................................. 24
4.5.2 Vector surge supervision ............................................................................................... 25
4.5.3 Measuring principle of vector surge supervision ........................................................... 26
4.5.4 Voltage threshold value for frequency, df/dt and vector surge measuring .................. 29
4.6 Over current- and short circuit supervision ....................................................................... 29
4.7 Earth fault protection ......................................................................................................... 30
4.7.1 Generator stator earth fault protection .......................................................................... 30
4.7.2 System earth fault protection ........................................................................................ 30
4.7.3 Earth-fault directional feature ........................................................................................ 31
4.7.4 Residual voltage ............................................................................................................ 33
4.7.5 Behavior of MRG3 under different operating conditions ............................................... 33
4.7.6 Blocking function set in compliance with requirements................................................. 33
4.8 Fault recorder .................................................................................................................... 34
5. Operation and Settings .............................................................................. 36
5.1 Display ............................................................................................................................... 36
5.2 Setting procedure .............................................................................................................. 40
5.3 Systemparameters ............................................................................................................ 40
5.3.1 Y – Change-over switch ................................................................................................ 40
5.3.2 Display of measurement values as primary quantity .................................................... 40
5.3.3 Setting of measured secondary values for the voltage transformers ............................ 40
5.3.4 Setting of the generator’s nominal values ..................................................................... 40
5.3.5 Voltage transformer connection for residual voltage measuring (3pha/e-n/1:1) ........... 41
5.3.6 Nominal frequency ........................................................................................................ 41
5.3.7 Selection between vector surge function or df/dt supervision ....................................... 41
5.3.8 Display of the activation storage ................................................................................... 41
5.3.9 Parameter changeover switch/external triggering of the fault recorder ........................ 42
5.4 Protection parameter “Mains decoupling” ......................................................................... 43
5.4.1 Parameter setting of “Over- and under voltage functions” ............................................ 43
5.4.2 Number of measuring repetitions (T) for frequency functions ....................................... 43
5.4.3 Threshold values of frequency supervision ................................................................... 44
5.4.4 Tripping delays for the frequency elements .................................................................. 44
5.4.5 Parameter setting for vector surge supervision or df/dt speed ..................................... 44
5.4.6 Settable threshold ......................................................................................................... 46
5.5 Protection parameter “Over current” ................................................................................. 46
5.5.1 Pickup value for phase over current element ................................................................ 46