1745
Users Manual
34
Calculation of THD in Measuring Function P
THD – Measuring Function P
Function P does not measure harmonic values.
Voltages:
1
2
1
2
V
V
V
THDV
RMS
−
=
V
RMS:
RMS value of the total signal
V
1
: RMS value of the fundamental
Currents:
1
2
1
2
I
I
I
THDI
RMS
−
=
I
RMS:
RMS value of the total signal
I
1:
RMS value of the fundamental
Note
THDI for currents < 5 % of IE (measuring range) can have
additional uncertainties, or can be suppressed.
Harmonics up to 50th order are taken into account.
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