GE Multilin G650 Manual page 153

5.2 PRODUCT SETUP
5.2.4.2 OSCILLOGRAPHY SETTINGS
These settings ("Setpoint > Product Setup > Oscillography") are described in Table 5–11:
Table 5–11: OSCILLOGRAPHY SETTINGS
SETPOINT > PRODUCT SETUP > OSCILLOGRAPHY
Setting Description
Function Permission
Prefault
Sampling rate
Maximum number of oscillos
Automatic oscillography overwrite
Snapshot Event generation
Function Permission (Function): Enabling this setting allows to create an oscillography record when the "TRIGGER
Trigger Position:
Sampling Rate:
Maximum Number of Oscillos (Max. Number Osc.):
5
Automatic Overwrite:
Snapshot Events:
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 3600 Hz as sampling rate , each record will store up to:
• 6898 / 72 = 95.78 signal cycles at 50 Hz as nominal frequency
• 6898 / 60 = 114.93 signal cycles at 60 Hz as nominal frequency
This value expressed in terms of time would be:
5-10
Name
Function
Trigger Position
Sampling Rate
Max. Number Osc.
Automatic Overwrite
Snapshot Events
OSCILLO" signal is activated.
This setting defines the prefault data (in percentage) stored every time a new oscillo is
produced.
This setting defines the sampling rate of the oscillography capture. Please see the
example below.
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/
measurement + 2 digital bytes) per stored sample. Please refer to example below.
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.
This setting enables or disables snapshot event generation for the oscillography
element.
For 50 Hz: 95.78 cycles x 20 ms/cycle =1.915 seconds.
For 60 Hz: 114.93 cycles x 16.67 ms/cycle =1.915 seconds.
G650 Generator Protection & Control System
Default Value Step Range
ENABLED N/A [DISABLED – ENABLED]
30 1% [5 : 95]
3600 Hz [225-450-900-1800-3600]
4 1 oscillo [1 : 20]
DISABLED N/A [DISABLED – ENABLED]
ENABLED N/A [DISABLED – ENABLED]
5 SETTINGS
GEK-113285A