GE N60 Instruction Manual page 225

5 SETTINGS
TRIGGER
REC
• PMU 1 RECORDING RATE: 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.
• PMU 1 NO OF TIMED RECORDS: This setting specifies how many timed records are available for a given logical
PMU. 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.
• PMU 1 TRIGGER MODE: This setting specifies what happens when the recorder uses its entire available memory
storage. If set to "Automatic Overwrite", the last record is erased to facilitate new recording, when triggered.
If set to "Protected", the recorder stops creating new records when the entire memory is used up by the old un-cleared
records. Refer to chapter 7 for more information on clearing PMU records.
The following set of figures illustrate the concept of memory management via the
Record
1
Record
1
Record
1
Record
6
Record
1
Record
1
Record
1
No further recording after all allocated memory is used
GE Multilin N60 Network Stability and Synchrophasor Measurement System
Figure 5–30: PMU RECORDING
Total memory for all logical PMUs
Memory available for the logical PMU
Record Record Free
2 3 memory memory
Record Record Record
2 3 4 memory
Record Record Record Record
2 3 4
Record Record Record Record
2 3 4
Figure 5–31: "AUTOMATIC OVERWRITE" MODE
Total memory for all logical PMUs
Memory available for the logical PMU
Record Record Free
2 3 memory memory
Record Record Record
2 3 4 memory
Record Record Record Record
2 3 4
Figure 5–32: "PROTECTED" MODE
PMU 1 TRIGGER MODE
Free
Other logical PMUs
Free
Other logical PMUs
Other logical PMUs
5
Other logical PMUs
5
Free
Other logical PMUs
Free
Other logical PMUs
Other logical PMUs
5
5.4 SYSTEM SETUP
847709A2.CDR
setting.
847705A1.CDR
847706A1.CDR
5-95
5