GEK-106426B
MIB High Impedance Bus Differntial Relay
2-11
2 PRODUCT DESCRIPTION
2.5 CALCULATION OF SETTINGS
2
OSCILLOGRAPHY
MIB stores an oscillography record, with a resolution of 8 samples per cycle with a length of 24 cycles (including 2 pre-fault
cycles), with the following information:
Instantaneous values of differential currents . The 2 first cycles are pre-fault cycles.
•
Digital information:
•
Pickups (protection functions)
•
Trip inhibition by digital input (protection functions)
•
Trips (protection functions)
•
Auxiliary digital outputs
•
Digital inputs
•
Date and time
•
Model
•
Number of oscillo
•
Value of the differential currents at the moment of the oscillography trigger
•
Active group at the moment of the oscillography trigger
•
Element settings when retrieving the oscillography record.
.
The number of oscillo is a circular counter that increases with each generated oscillography. This value appears on the
relay status and is used only for informative purposes.
The oscillography record is stored in a capacitor backed up RAM memory.
MIB functionality related to oscillography is performed from the ENERVISTA MII SETUP program. The oscillography record
obtained is stored on the PC in a COMTRADE-IEEE C37.111-1991 format.
There are four possible causes that can produce an oscillography trigger:
1.
Pickup of one of the protection functions
87 2 Disable by input
Yes
Trip disabled (by DI)
Yes
Protection status
Yes
Output 1
Yes
Output 2
Yes
Output 3
Yes
Output 4
Yes
Digital Input 1
Yes
Digital Input 2
Yes
Sett. change disable
Yes
Trip operation by input
Yes
Trip operation by command
Yes
Reset latch aux
Yes
Settings group change
Yes
Oscillo trigg by DI
Yes
86 Status
Yes
Reset 86
Yes
Oscillo trigg by comm
Yes
Settings change
Yes
EEPROM Failure
Yes
User settings
Yes
Table 2–1: LIST OF EVENTS
