Schweitzer Engineering Laboratories SEL-311C - Figure 12.4 Derivation of Event Report Current Values and RMS Current Values from Sampled Current Waveform

12.25
Date Code 20060320 Instruction Manual SEL-311C Relay
Standard Event Reports and SER
Example Standard 15-Cycle Event Report
Figure 12.4 Derivation of Event Report Current Values and RMS Current Values From Sampled Current
Waveform
In Figure 12.4, note that any two rows of current data from the event report in
Figure 12.3, 1/4 cycle apart, can be used to calculate rms current values.
= 2475
(1531)
2
+ (1945)
2
= 2478
(–1532)
2
+ (–1948)
2
event report column
= 2478
(–1948)
2
+ (1531)
2
–1532
–1948
1531
1945
1945
1531
–1948
–1532
IB
RMS
= 2477 A
3503 A
peak
2
1
2
multiply by
2
1
multiply by
1945
–1948
1531
–1532
2165
–2755
–2167
2751
t
peak
peak
= 3503 A
IB
4
1
cyc
IB
Raw Waveform