Appendix 3 Event Detection Methods
A
10
Voltage DC Value, Current DC Value (CH4 only)
Measurement method:
Values are detected when the average value for the approx. 200 ms aggregation synchronized to the reference channel
U1 exceeds a threshold specified as an absolute value.
Event IN and OUT:
Event IN : Start of the approx. 200 ms aggregation in which the reading is greater than the upper limit or less than the
lower limit
Event OUT : Start of the first approx. 200 ms aggregation in which the reader is less than (the upper limit - hysteresis)
after being greater than the upper limit, or in which the reading is greater than (the lower limit + hysteresis)
after being less than the lower limit
Voltage DC Change and Current DC Change (CH4 only)
Measurement method:
DC fluctuation events are detected when the difference between the positive and negative waveform peak values in an
approx. 200 ms aggregation exceeds the set threshold.
Measured values in the event list are displayed as the voltage or current value for the difference between the positive and
negative waveform peak values. (These measured values are not recorded.)
Sampled waveform
Positive waveform peak value
DC value (average value)
Negative waveform peak value
Approx. 200 ms
aggregation
Event IN Event OUT
Approx. 200 ms
aggregation
Approx. 200 ms
aggregation
Approx. 200 ms
aggregation
Difference between positive
and negative waveform peak
values
Voltage Unbalance Factor, Current Unbalance Factor, Harmonic Voltage,
Harmonic Current, Harmonic Power, Harmonic Voltage-Current Phase Dif-
ference, Total Harmonic Voltage Distortion Factor, Total Harmonic Current
Distortion Factor, and K Factor
Measurement method:
Measured values are calculated for a rectangular window of 4,096
points in an approx. 200 ms aggregation of 10 cycles (50 Hz), 12
cycles (60 Hz), or 80 cycles (400 Hz), and events are detected
when the calculated values are greater than or less than the cor-
responding threshold.
Event IN and OUT:
Event IN : Start of the approx. 200 ms aggregation in which the
reading is greater than the threshold
Event OUT : Start of the approx. 200 ms aggregation in which the
reading is less than (the threshold - hysteresis)
50 Hz: 10 cycles, 60 Hz: 12 cycles, 400 Hz: 80 cy-
cles
Harmonic calculation using rectangular window
3rd-order harmonic voltage
Hysteresis
Threshold
EVENT
OUT
EVENT
IN