Schweitzer Engineering Laboratories SEL-351 - Compressed ASCII Event Reports; Filtered and Unfiltered Event Reports

Date Code 20001006 Standard Event Reports, Sag/Swell/Interruption Report, and SER
SEL-351 Instruction Manual
12-7
Serial Port
Command Description
EVE Display the most recent event report at 1/4-cycle resolution.
EVE 2 Display the second event report at 1/4-cycle resolution
EVE S16 L10 Display 10 cycles of the most recent report at 1/16-cycle resolution.
EVE C 2 Display the second report in Compressed ASCII format at 1/4-cycle resolution.
EVE L Display most recent report at 1/16-cycle resolution.
EVE R Display most recent report at 1/16-cycle resolution; analog and digital data are
unfiltered (raw).
EVE 2 D L10 Display 10 cycles of the protection and control elements section of the second
event report at 1/4-cycle resolution.
EVE 2 A R S4 Display the unfiltered analog section of the second event report at 1/4-cycle
resolution.
If an event report is requested that does not exist, the relay responds:
“Invalid Event”
Compressed ASCII Event Reports
The SEL-351 Relay provides compressed ASCII event reports to facilitate event report storage and
display. The SEL-2020 Communications Processor and the SEL-5601 Analytic Assistant
software take advantage of the compressed ASCII format. Use the EVE C command or CEVENT
command to display compressed ASCII event reports. See the CEVENT command discussion in
Appendix E: Compressed ASCII Commands for further information.
Filtered and Unfiltered Event Reports
The SEL-351 Relay samples the basic power system measurands (ac voltage, ac current, station
battery, and optoisolated inputs) 16 times per power system cycle. The relay filters the
measurands to remove transient signals. The relay operates on the filtered values and reports them
in the event report.
To view the raw inputs to the relay, select the unfiltered event report (e.g., EVE R). Use the
unfiltered event reports to observe:
• Power system harmonics on channels IA, IB, IC, IN, VA, VB, VC, VAB, VBC, VCA,
VS
• Decaying dc offset during fault conditions on IA, IB, IC
• Optoisolated input contact bounce on channels IN1 through IN8 (model 0351xT) or
channels IN101 through IN106 (Models 0351x0 and 0351x1)
• Transients on the station dc battery channel Vdc (power input terminals Z15 and Z16)
Courtesy of NationalSwitchgear.com