GE Multilin W650, Instruction Manual

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5-10 W650 Wind Generator Protection System GEK-113032A
5.2 PRODUCT SETUP 5 SETTINGS
5
Function Permission (Function): Enabling this setting allows to create an oscillography record when the “ TRIGGER
OSCILLO ” signal is activated.
Trigger Position: This setting defines the prefault data (in percentage) stored every time a new oscillo is
produced.
Samples/Cycle: This setting defines the number of samples per cycle stored in each oscillography
record. Please see the example below.
Maximum Number of Oscillos (Max. Number Osc.): 1 to 20 oscillography records can be selected. The capacity of each
record is = 1Mbyte / Max. Number Osc. This capacity is divided in 38 bytes (9
measurements * 4 bytes/measu 2 digital bytes) per stored sample. Please
refer to example below.
Automatic Overwrite: This setting allows chained oscillographies during the fault (TRIGGER OSCILLO signal
activated). The maximum allowed value to be stored as a chained oscillography is 1
Mbyte. In this case, even if the trip continues during a time longer than the associated
1 Mbyte of memory, the relay will stop storing the oscillography in RAM memory until
the complete record has been saved in non-volatile memory. The oscillography
module will be reset once the data has been completely stored in Flash memory and
the TRIGGER OSCILLO state is deactivated.
Snapshot Events: This setting enables or disables snapshot event generation for the oscillography
element.
EXAMPLE
For a Max. Number Osc. of 4, each record will store 1Mbyte / 4 = 262144 bytes.
Therefore, the number of samples per oscillography record is 262144 bytes / 38 bytes = 6898 samples per stored oscillo.
If we set the relay to 64 samples per cycle, each record will store up to 6898 / 64 = 107.78 signal cycles. This value
expressed in terms of time would be:
For 50 Hz: 107.78 cycles x 20 ms/cycle =2.155 seconds.
For 60 Hz: 107.78 cycles x 16.67 ms/cycle =1.796 seconds.