Thytronic NC020 - Oscillography - DFR

MEASURES, LOGIC STATES AND COUNTERS
53
NC020 - Manual - 05 - 2022
— Oscillography - DFR
[1]
Upon programmable trigger, the fault records are recorded in COMTRADE
[2]
format; the sampled
measures (16 sample per cycle) are stored in a circular memory buffer.
The fault record are self-triggered; two records are stored in sequential order.
An operating procedure example for the digital fault recording is illustrated inside the ThyVisor sec-
tion.
Following parameters are user-programmable:
[3]
• Pre-trigger time (0...63 T where T = number of power cycles; Example, with settings T=4 the pre-trig-
ger duration is 80 ms with f = 50 Hz).
• Selected sampled quantities.
• Analog channels (1...4) allocation.
• Digital channels allocation (output relay and/or binary inputs).
• Trigger setup; the information storage starts when a state transition on the selected signal occurs.
(protective element start and/or trip, output relay and/or binary input switching).
Since the buffer size fixed, the duration of the two recordings is variable and is then given the user-
defined setting, with the following parameters:
• Pre-trigger times (number of periods)
• Number of allocated channels.
Example 1
With the following setting:
• Analog channel 1: i
L1
• Analog channel 2: i
L2
• Analog channel 3: i
L3
• Analog channel 4: i
N
• Digital channel: K1
• Pre-trigger: 1 T (20 ms)
the stored record length of the two records with f = 50 Hz is 240 ms
Example 2
With the following setting:
• Analog channel 1: i
L1
• Analog channel 2: -
• Analog channel 3: -
• Analog channel 4: -
• Digital channel: K1
• Pre-trigger: 1 T (20 ms)
the stored record length of the two records with f = 50 Hz is 640 ms
Note 1 The oscillographic recorder requires a licence; to purchase it please contact Thytronic.
Note 2 COMTRADE format; (Common Format for Transient Data); This is a standard for the data exchange for various types of tests or simulation data,
etc, for power system applications.
The measurements are recorded in ASCII or BINARY format. COMTRADE files always come by pairs:
The “.CFG”-file describing the configuration: number of analog and digital channels, sampling rate, scale factors, etc.
The “.DAT”-file containing the data
The COMTRADE is part of IEC 60255-24 standard.
The recording can be analyzed by mean of ThyVisor sw or any other standard compliant viewer.
Note 3 As all settings, the settings take effect only after sending the Store command
trigger.ai
Trigger
Time
pre-trigger
record length
post-trigger
0...63 T
trigger.ai
Trigger
Time
240 ms
1 T
20 ms