ABB REB650, Technical Manual

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Disturbance recorder collects analog values and binary signals continuously, in a cyclic
buffer. The pre-fault buffer operates according to the FIFO principle; old data will
continuously be overwritten as new data arrives when the buffer is full. The size of this
buffer is determined by the set pre-fault recording time.
Upon detection of a fault condition (triggering), the disturbance is time tagged and the
data storage continues in a post-fault buffer. The storage process continues as long as
the fault condition prevails - plus a certain additional time. This is called the post-fault
time and it can be set in the disturbance report.
The above mentioned two parts form a disturbance recording. The whole memory,
intended for disturbance recordings, acts as a cyclic buffer and when it is full, the
oldest recording is overwritten. Up to the last 100 recordings are stored in the IED.
The time tagging refers to the activation of the trigger that starts the disturbance
recording. A recording can be trigged by, manual start, binary input and/or from analog
inputs (over-/underlevel trig).
A user-defined name for each of the signals can be set. These names are common for
all functions within the disturbance report functionality.
12.8.5.1 Memory and storage
The maximum number of recordings depend on each recordings total
recording time. Long recording time will reduce the number of
recordings to less than 100.
The IED flash disk should NOT be used to store any user files. This
might cause disturbance recordings to be deleted due to lack of disk space.
When a recording is completed, a post recording processing occurs.
This post-recording processing comprises:
• Saving the data for analog channels with corresponding data for binary signals
• Add relevant data to be used by the Disturbance handling tool (part of PCM 600)
• Compression of the data, which is performed without losing any data accuracy
• Storing the compressed data in a non-volatile memory (flash memory)
The recorded disturbance is now ready for retrieval and evaluation.
The recording files comply with the Comtrade standard IEC 60255-24 and are divided
into three files; a header file (HDR), a configuration file (CFG) and a data file (DAT).
1MRK 505 277-UUS C
Section 12
Monitoring
289
Technical Manual