Hioki 9605-01, Инструкция по эксплуатации, Страница: 22 / 100

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4.1 Harmonic Measurement
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NOTE
4.1 Harmonic Measurement
The 9605-01 HARMONIC MEASUREMENTS UNIT applies FFT (Fast-
Fourier Transform) analysis to waveforms from the A/D converter for each
window, and can analyze voltage, current and power harmonics. Up to 3,000
degrees can be analyzed, and fundamental frequencies from 10 Hz to 4.5
kHz are supported.
･
Because of differences in measurement principle, frequency response, and
accuracy, the values measured by the 9605-01 and 9600/9601/9602 products
installed in the same 3194 product may not agree. Similarly, values may not
agree with measurements made by other devices.
･ If the PLL synchronization range is 10 Hz to 17.5 Hz or 17.5 Hz to 35 Hz,
then the anti-aliasing filter of Fc
≒
15 kHz is inserted. If the PLL
synchronization range is 35 Hz or more, then the anti-aliasing filter of Fc
≒
120 kHz is inserted.
･
Although harmonics can be analyzed at up to 3,000 degrees, only a
maximum of 50 items can be displayed on the screen.
･
Because items not displayed are calculated internally at the same time, by
switching to the hold state and switching the screen, it is possible to read
simultaneous values for other analysis data.
･
Be sure to carry this out with the PLL in the locked state.
･
The harmonics which can be analyzed depend on the frequency of the PLL
source. For details see the Specifications.
･
Color specifications are not possible.
･
The zeroth index is displayed when using a 9600/9602 with AC+DC or DC
mode selected. This zeroth index is the DC component of the analyzed
waveform. In the voltage/current mode, effective values are computed, and
there is therefore no polarity. The accuracy of the zeroth index is not
specified.
･
When using 3P3W/3V3A mode, analysis results for power signify the total
values ( Σ P). The power analysis results are shown for each channel, but
these have no significance. The total value (
Σ
P) is the same result for 3P3W
and 3V3A.
･
The phase angle indicates the phase angle of all data, taking the phase angle
of the fundamental from the PLL source as 0
。
. For the total value (
Σ
P) , the
phase angle is not displayed.
･
The phase difference indicates the phase difference of the current with
respect to the voltage on the same channel for each harmonic.
･ At less than 0.1% of range, internal circuit noise may appear in the
display.
･ When the rms value of voltage or current exceeds 130% of range, or when
the peak value of voltage or current exceeds crest factor, the value of
analysis data and power analysis data is shown in red.