Power quality analysis functions
11.1 Power quality analysis status
Analog input module AI Energy Meter 480VAC/CT HF (6ES7134-6PA00-0CU0)
Manual, 07/2018, A5E42674880-AA
89
Harmonics are superimposed vibrations deviating from the fundamental frequency of the
supply network (50 Hz or 60 Hz) with an integer multiple of the fundamental frequency.
Harmonics are generated by equipment with a non-linear current–voltage characteristic such
as transformers, gas discharge lamps and power electronics devices.
Harmonic component THD (Total Harmonic Distortion)
The THD defines the ratio of the power of the harmonics to the power of the fundamental
and provides information about the power quality. The value is dimensionless and is stated
as a percentage [%].
The AI Energy Meter HF returns THD+N (Noise) and considers the entire current signal
(DS 163) or voltage signal (DS 161). Interference in the network is not filtered out.
Power quality analysis status
Information about the power quality status can be found in the measured value "Power
quality analysis qualifier" with the measured value ID 65496.
The bits 0 to 4 in byte 1 to 3 show in status "1" that information has been available since the
last reset, which can be retrieved. The bits 5 to 7 in byte 1 to 3 in status "1" show that the
event is currently active. If the event is not active, "0" is displayed.
The measured value "Network analysis qualifier" has the following structure:
Byte 0 Power quali-
ty analysis
qualifier
module
Reserved Reserved Status of harmonics analysis:
0
D
: No data, no start
1
D
… 62
D
: running
D
: Completed, data is available
Byte 1 Power quali-
ty analysis
qualifier
Event
currently
active
Event
currently
active
Event
currently
active
Event
occurred,
data
available
Event
occurred,
data
available
Event
occurred,
data
available
Event
occurred,
data
available
Event
occurred,
data
available
Byte 2 Power quali-
ty analysis
qualifier
Byte 3 Power quali-
ty analysis
qualifier