PQM-700 Operating Manual
30
Fig. 15. Determination of harmonic subgroups (50 Hz system).
The IEC 61000-4-30 standard recommends that the harmonic subgroup method is used in
power quality analyzers.
4.7
Event detection
The PQM-700 analyzer gives a lot of event detection options in the tested mains system. An
event is the situation when the parameter value exceeds the user-defined threshold.
The fact of event occurrence is recorded on the memory card as an entry which includes:
parameter type,
channel in which the event occurred,
times of event beginning and end,
user-defined threshold value,
parameter extreme value measure during the event,
parameter average value measure during the event.
Depending on the parameter type, you can set one, two or three thresholds which will be
checked by the analyzer. The table below lists all parameters for which the events can be detected,
including specification of threshold types.
Example
In order to calculate the 3
rd
harmonic component in the 50 Hz system, use
the 150 Hz main spectral line and neighboring 145 Hz and 155 Hz lines.
The resultant amplitude is calculated with the RMS method.
Summary of Contents for PQM-700
Page 85: ...85 Notes...
