MI 2792 PowerQ4 Plus
Theory and internal operation
110
with the time of the end of the U
Rms(1/2)
that ended the event, as defined by the
threshold.
The duration of a voltage dip is the time difference between the start time and the
end time of the voltage dip.
Figure 5.8 Voltage events definition
Voltage swell
Standard compliance: IEC 61000-4-30 Class S (Section 5.4.3)
The swell threshold is a percentage of nominal voltage defined in Voltage events setup
menu. The swell threshold can be set by the user according to the use. Instrument
permits swell evaluation:
on single-phase systems, a voltage swell begins when the U
Rms(1/2)
voltage rises
above the swell threshold, and ends when the U
Rms
voltage is equal to or bellow
the swell threshold plus the 2% of hysteresis voltage (see Figure 5.8),
on three-phase systems two different evaluation techniques can be used for
evaluation simultaneously:
o
A swell begins when the U
Rms(1/2)
voltage of one or more channels is
above the swell threshold and ends when the U
Rms(1/2)
voltage on all
measured channels is equal to or bellow the swell threshold plus the 2%
of hysteresis voltage.
o
A swell begins when the U
Rms(1/2)
voltage of one channel rises above the
swell threshold, and ends when the U
Rms(1/2)
voltage is equal to or bellow
the swell threshold plus the 2% of hysteresis voltage, on the same phase.
A voltage swell is characterized by a pair of data: maximum swell voltage magnitude,
and duration:
