GE MiCOM P40 Agile Technical Manual page 398

P44x/EN MR/Hb6
(MR) 7-12
1.3 Disturbance recorder
The integral disturbance recorder ("Disturb recorder" menu, P44x/EN ST) has an area of
memory specifically set aside for record storage. The number of records that may be stored
is dependent upon the selected recording duration but the relays typically have the capability
of storing a minimum of 20 records, each of 10.5 second duration.
Note:
Disturbance records continue to be recorded until the available memory is exhausted, at
which time the oldest record(s) are overwritten to make space for the newest one.
The recorder stores actual samples which are taken at a rate of 24 samples per cycle.
It is not possible to view the disturbance records locally via the LCD; they must be extracted
using suitable software such as MiCOM S1 Agile. This process is fully explained in the
SCADA Communications section (P44x/EN SC).
1.4 Fault locator
The relay has an integral fault locator that uses information from the current and voltage
inputs to provide a distance to fault measurement. The sampled data from the analogue
input circuits is written to a cyclic buffer until a fault condition is detected. The data in the
input buffer is then held to allow the fault calculation to be made. When the fault calculation
is complete the fault location information is available in the relay fault record.
When calculated the fault location can be found in the fault record under the
VIEW RECORDS column in the Fault Location cells. Distance to fault is available in km,
miles, impedance or percentage of line length. The fault locator can store data for up to five
faults. This ensures that fault location can be calculated for all shots on a typical multiple
reclose sequence, whilst also retaining data for at least the previous fault.
1. Compressed Disturbance Recorder used for Kbus/Modbus/DNP3 reach that
typical size value (10.5 sec duration)
2. Uncompressed Disturbance Recorder used for IEC 60870-5/103 could be
limited to 2 or 3 secondes.
Measurements and Recording
MiCOM P442 & P444