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1
1.1
1.1.1
1.2
94
Disturbance report (DRP)
Disturbance report (DRP)
Application
Use the disturbance report to provide the network operator with proper information about dis-
turbances in the primary network. The function comprises several subfunctions enabling differ-
ent types of users to access relevant information in a structured way.
Select appropriate binary signals to trigger the red HMI LED to indicate trips or other important
alerts.
Requirement of trig condition for disturbance report
Disturbance reports, setting and internal events in REx 5xx are stored in a non volatile flash
memory. Flash memories are used in many embedded solutions for storing information due to
high reliability, high storage capacity, short storage time and small size.
In REx 5xx there is a potential failure problem, caused by too many write operations to the flash
memory.
Our experience shows that after storing more than fifty thousand disturbances, settings or inter-
nal events the flash memory exceeds its storing capacity and the component is finally defected.
When the failure occurs there is no risk of unwanted operation of the protection terminal due to
the self-supervision function that detects the failure. The terminal will give a signal for internal
fail and go into blocking mode.
The above limitation on the storage capacity of the flash memory gives the following recom-
mendation for the disturbance report trig condition:
•
Cyclic trig condition more often then once/day not recommended.
•
Minute pulse input is not used as a trig condition.
•
Total number of stored disturbance reports shall not exceed fifty thousand.
Functionality
The disturbance report collects data from each subsystem for up to ten disturbances. The data is
stored in nonvolatile memory, used as a cyclic buffer, always storing the latest occurring distur-
bances. Data is collected during an adjustable time frame, the collection window. This window
allows for data collection before, during and after the fault.
The collection is started by a trigger. Any binary input signal or function block output signal can
be used as a trigger. The analog signals can also be set to trigger the data collection. Both over
levels and under levels are available. The trigger is common for all subsystems, hence it acti-
vates them all simultaneously.
A triggered report cycle is indicated by the yellow HMI LED, which will be lit. Binary signals
may also be used to activate the red HMI LED for additional alerting of fault conditions. A dis-
turbance report summary can be viewed on the local HMI.
Chapter 8
Monitoring
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