METREL MI 3399, Инструкция с упражнениями

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Power and Voltage Quality Trainer AD 2
– MI 3399
177
By observing large differences between maximum ( ), average ( ) and
minimum ( ) recorded values within a single interval we can conclude that a
switching load is present. See figure below.
Figure 4-56: Observing power on switching load
On phase L3 we added a 3
rd
harmonic on current. As a consequence of current
harmonics, nonfundamental apparent power (S
N
) and phase current distortion power
(Di) is introduced as shown in the figure below.
Figure 4-57: Observing power on inductive load with 10% of third harmonics on
current channel I
3
Finish recording by entering the RECORDERS

GENERAL RECORDER menu, and
pressing the F1 (STOP) key. The stored record can be observed on the instrument or
transferred to PowerView. Import your recordings into Metrel PowerView software, as
described in section 4.1.3. All Power and energy related measurements can be
accessed using the
“Power & Energy option” in the “Data explorer” tab. Current, active
consumed power, reactive consumed power and Power Factor are shown below for
example. Note that there is a large difference between Average and Active average
(AvgOn) values in graphs, which clearly indicates that we are dealing with switch load.