Oscillography - GE Multilin MIWII Instruction Manual

2 PRODUCT DESCRIPTION

2.8 OSCILLOGRAPHY

2.8OSCILLOGRAPHY
The MIWII stores an oscillography record, with a resolution of 8 samples per cycle, and a length of 24 cycles (the 2 first
being pre-fault cycles), every time the oscillography is triggered.
The oscillography record is stored in a capacitor backed up RAM memory, which maintains the information during more
than one weed without auxiliary voltage.
The whole MIWII 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.
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In order to view the created record, we can use any software package that can open COMTRADE files, such as GE-OSC.
We can also use a calculation sheet program that can import CSV format, such as Microsoft Excel, and then use the
graphical tools to view the waveform information.
In the ADVANCED SETTINGS group, there is a sub-group called OSCILLOGRAPHY MASKS, from where the above
mentioned causes can be masked. They are detailed in the SETPOINT – SETPOINT – ADVANCED SETTINGS –
OSCILOGRAPHY MASK section.
There are four possible causes that can produce an oscillography trigger:
Pickup of one of the protection functions
Trip of one of the protection functions
Oscillography trigger by communications
Oscillography trigger by digital input
The information included in the oscillography record is as follows:
GEK-113308 MIWII Directional Power Protection System 2-13