CHAPTER 11: METERING
PHASOR MEASUREMENT UNIT
D90
PLUS
LINE DISTANCE PROTECTION SYSTEM – INSTRUCTION MANUAL
549
Figure 478: Phasor measurement unit recording configuration settings
The following settings are available for each phasor measurement unit.
Recording Rate
Range: 1, 2, 5, 10, 12, 15, 20, 25, 30, 50, or 60 times per second
Default: 10 times per second
This setting specifies the recording rate for the record content. Not all recording rates
are applicable to either 50 or 60 Hz systems (for example, recording at 25 phasors a
second in a 60 Hz system). The relay supports decimation by integer number of phasors
from the nominal system frequency. If the rate of 25 is selected for the 60 Hz system, the
relay would decimate the rate of 60 phasors a second by round (60 / 25) = 2; that is, it
would record at 60 / 2 = 30 phasors a second.
Number of Timed Records
Range: 1 to 128 in steps of 1
Default: 3
This setting specifies how many timed records are available for a given logical phasor
measurement unit. The length of each record equals available memory divided by the
content size and number of records. The higher the number of records, the shorter each
record. The relay supports a maximum of 128 records.