![ABB A43 User Manual Download Page 52](http://html.mh-extra.com/html/abb/a43/a43_user-manual_4297052.webp)
Technical Description
A43/A44
52
2CMC48001M0201
User Manual
Revision: C
5.3.1 Measuring Harmonics
General
To detect and eliminate the problems related to presence of harmonics, it’s gener-
ally necessary to measure the harmonics. Meters that have harmonic measure-
ment enabled measure harmonics on all voltages and currents up to the 16th har-
monic and calculates the total harmonic distortion (THD).
Measuring
Measurement of the harmonics is done sequentially, one at a time, and approxi-
mately two harmonic numbers are measured every second.
Each harmonic is calculated according to:
and the total current harmonic distortion for the harmonics measured is
calculated according to:
where
I
f
is the fundamental current and
I
n
is the current for harmonics with num-
ber n.
At each measurement the harmonic is set to 0 if the rms value of the current is
below a certain lower limit (normally 5% of the basic current).
Folding distortion
Since the meter have limited sampling frequency, presence of harmonics over the
20:th harmonic (1 kHz at 50 Hz line frequency) will result in folding distortion
and can affect the harmonic measurement accuracy negatively.
Due to the possible presence of folding distortion and the fact that harmonics is
measured sequentially, one at a time, it is recommended that the harmonic mea-
surement results of the meter is used as a tool to detect presence of harmonics and
not as an exact instrument to get exact results.
Frequency
Measuring harmonics require a valid frequency measurement. If the frequency
measurement
measurement is uncertain, the harmonic measurement will not be performed. To
get a valid measurement the meter uses a retry scheme. If the retry scheme does
not give a valid measurement the harmonic will be marked as "not available".
Summary of Contents for A43
Page 1: ...A43 A44 User Manual ...
Page 40: ...Meter Settings A43 A44 40 2CMC48001M0201 User Manual Revision C ...
Page 55: ...Technical Description 2CMC48001M0201 55 A43 A44 Revision C User Manual ...
Page 58: ...Technical Description A43 A44 58 2CMC48001M0201 User Manual Revision C ...
Page 61: ...Technical Description 2CMC48001M0201 61 A43 A44 Revision C User Manual ...
Page 75: ...Technical Description 2CMC48001M0201 75 A43 A44 Revision C User Manual ...
Page 84: ...Measurement Methods A43 A44 84 2CMC48001M0201 User Manual Revision C ...
Page 91: ...Measurement Methods 2CMC48001M0201 91 A43 A44 Revision C User Manual ...
Page 95: ...Measurement Methods 2CMC48001M0201 95 A43 A44 Revision C User Manual ...
Page 102: ...Communication with Modbus A43 A44 102 2CMC48001M0201 User Manual Revision C ...
Page 107: ...Communication with Modbus 2CMC48001M0201 107 A43 A44 Revision C User Manual ...
Page 131: ...Communication with Modbus 2CMC48001M0201 131 A43 A44 Revision C User Manual ...
Page 147: ...Communication with Modbus 2CMC48001M0201 147 A43 A44 Revision C User Manual ...
Page 154: ...Communication with Modbus A43 A44 154 2CMC48001M0201 User Manual Revision C ...
Page 157: ...Communication with Modbus 2CMC48001M0201 157 A43 A44 Revision C User Manual ...
Page 161: ...Communication with Modbus 2CMC48001M0201 161 A43 A44 Revision C User Manual ...
Page 166: ...Communication with Modbus A43 A44 166 2CMC48001M0201 User Manual Revision C ...
Page 180: ...Communication with M Bus A43 A44 180 2CMC48001M0201 User Manual Revision C ...
Page 182: ...Communication with M Bus A43 A44 182 2CMC48001M0201 User Manual Revision C ...
Page 188: ...Communication with M Bus A43 A44 188 2CMC48001M0201 User Manual Revision C ...
Page 195: ...Communication with M Bus 2CMC48001M0201 195 A43 A44 Revision C User Manual ...
Page 254: ...Communication with M Bus A43 A44 254 2CMC48001M0201 User Manual Revision C ...
Page 257: ...Communication with M Bus 2CMC48001M0201 257 A43 A44 Revision C User Manual ...