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Harmonics (Addr.221)
Harmonics are the integer multiple of the funda-
mental wave. The UMG96S measures the
fundamental of voltage in the range of 45 to 65
Hz. The calculated harmonic voltage and current
is related to this fundamental. For strongly
distorted voltage, the fundamental cannot be
determined accurate enough. In order to be able
to calculate the harmonics nevertheless, a fix
fundamental of 50 or 60Hz can be selected.
Please see chapter "scanning frequency".
The UMG96S calculates harmonics up to the
15th multiple of the fundamental.
PRG
MkWh
MkVArh
L1
L2
L3
k A
In this example, the 15th harmonic of current in
L3 is indicated.
Number of partial
harmonic
Current har-
monic
Phase L3
Measured value
Total harmonic distortion factor THD
(Addr.269)
The total harmonic distortion factor, which is
calculated by UMG96S for current and voltage,
represents the ratio of the effective value of the
distorted quantity compared to the effective
value of the measured quantity. The total har-
monic distortion factor is given in per cent:
Total harmonic distortion of current THDI:
Partial harmonics (Addr.221)
In the further description, the single harmonics
are described as partial harmonics.
The partial harmonics of the current are given
in Ampere and the partial harmonics of voltage
are given in Volt.
Total harmonic distortion of voltage THDU:
I
2
1
2
THD
II
I
=
-
x 100%
U
2
1
2
THD
UU
U
=
-
x 100%
PRG
MkWh
MkVArh
L1
L2
L3
Voltage,
Phase L3-N
In this example, the total harmonic distortion
factor THD of voltage is indicated for phase L3.
Value
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