3-phase voltage sags, swells, and interruptions events:
A full description of the algorithm is found in chapter 5.4.2 and 5.4.3 of the IEC 61000-4-30 Ed3.
A 3-phase sag starts as soon as one of the phase U
rms (1/2)
values amplitude crosses the sag (lower)
threshold and ends when all 3 phase-voltage amplitudes are back within the threshold plus the
hysteresis.
A 3-phase swell starts as soon as one of the phase U
rms (1/2)
values crosses the swell (upper) threshold
and ends when all 3 phase U
rms (1/2)
are back within the threshold minus the hysteresis.
A 3-phase interruption starts when all 3 phase U
rms (1/2)
values cross the swell (upper) threshold and
ends when at least one of the phase-voltage “half cycle” amplitudes are back within the threshold
plus the hysteresis.
Frequency Events:
Frequency events are based on frequency measurements done based on counting of zero crossings
on a given period. The frequency triggering method uses a frequency refreshed every cycle, and
the value is computed on the window of 64 cycles.
Note: The PQube 3 also computes frequency aggregated at a 10s interval as per IEC 61000-4-30
Ed3. This frequency aggregation, however, is not used for triggering, but is recorded in a specific
10s frequency file.
Inrush Current Events:
Inrush triggers have thresholds for magnitude and time. If the current increases by the Inrush
Threshold value or more, within the specified time period or less, the PQube 3 will trigger an inrush
current event.
Wave Shape Change Events:
Your PQube 3 triggers a wave shape change when the voltage waveform changes abruptly. It uses
the “floating window” algorithm to compare each cycle to the previous cycle. It is especially useful
for detecting Power Factor Correction capacitor switching.
If the voltage changes from one cycle to the next exceeds the selected threshold and duration, your
PQube 3 will trigger a Waveshape change.
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