IEC61000-3 S
OFTWARE FOR
W
INDOWS
U
SER
M
ANUAL
R
EFERENCE
I
NFORMATION
Voltech Instruments
VPN 98-025/7
Page 73
6. R
EFERENCE
I
NFORMATION
Some of the information contained in this section is extracted from the
versions of the standards available at the time of publication. Please refer
to the relevant standards in force at the time of test for up to date
information.
6.1.
H
OW THE
A
NALYSER
P
ERFORMS A
2001 E
DITION
H
ARMONICS
T
EST
2001 measurement methods
The 2001 edition of IEC61000-3-2 defines exactly how the harmonic data
from a Power Analyzer must be used when comparing them to the
applicable limits.
(from section 6.2.2)
The measurement of harmonic currents shall be performed as follows:
•
For each harmonic order, measure the 1.5 s smoothed rms harmonic
current in each DFT time window….
(This is the same method used in previous versions. The analyzer
calculates all 40 harmonic amplitudes every 16 cycles of the supply
waveform without gaps or overlap. Each of the 40 harmonic
amplitudes is smoothed by a filter with a 1.5 second time constant)
•
Calculate the arithmetic average of the measured values from the
DFT time windows over the entire observation…..
Also the input power, fundamental current and power factor are required to
be measured in a very specific way. (These values are used to compute the
limits for certain classes). Measurements of POHC and THC are also
required for comparison with the limits and to determine test conditions.
These measurements are then compared to the limits in very specific ways.