Hioki 3196 - Event Detection Method

7.2 Event Detection Method
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7.2 Event Detection Method
Transient overvoltage
Detection method:
The voltage channels (U1 to U4) are sampled at 2
MHz and transients exceeding the absolute value of
the threshold are detected.
Threshold determines the variance from the voltage
waveform.
The waveform that is saved is the one that has the
largest positive or negative transient peak.
Recorded contents:
1. Peak value:
Maximum absolute value (2000 Vmax)
2. Interval:
Period over which the threshold is exceeded (4
msmax)
3. Waveform:
Waveform centered around the peak value
Threshold
Peak value
Threshold
Interval
2 ms
2 ms
Voltage swells, voltage dips, and interruptions
Detection method:
When measuring at 50 Hz or 60 Hz, events are
detected using the RMS voltage of sampling data for
a single wave (256 points) from a voltage waveform
that is shifted by a half cycle.
When measuring at 400 Hz, events are detected
using the RMS voltage of the sampling data for one
full cycle (32 points).
Detection is based on the line-to-line voltage with three-
phase three-wire connection, and on the phase-to-neu-
tral voltage with three-phase four-wire connection.
Swell is detected when the RMS voltage RMS
exceeds the threshold in the positive direction.
Dips and interruptions are detected when the RMS
voltage exceeds the threshold in the negative direc-
tion.
(Hysteresis is applied for detection in both cases.)
Recorded contents:
1. Height, depth:
For swell, the threshold is the height, and is dis-
played as swell to %.
For dips, the threshold is the depth, and is dis-
played as dip to %.
For interruptions, the threshold is the depth, and
is displayed as interruption to %.
2. Interval:
Period over which the threshold is exceeded
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RMS voltage
Threshold
Swell
D
ips and interruptions
Hysteresis
RMS voltage
RMS voltage
EVENT IN EVENT OUT
Hysteresis
Threshold
EVENT IN EVENT OUT