Siemens SENTRON PAC4220 - 2.6 Technical Features of Network Quality

2.6 Technical features of the network quality
The PA
C4220 supplies the following measured variables for evaluating network quality:
• Harmonics up to the 64thharmonic
• THD for voltage and current:
• Displacement angle φ
• Cosine of the displacement angle φ
• Phase angleU
• Unbalance voltage and unbalance current
Measurement of 1st to 64thharmonics for voltage and current
Harmonics are mainly caused by equipment with a non-linear characteristic, such as
󹪞uorescent lamps, transformers and frequency converters. They are integer multiples of a
fundamental.
The PAC4220 can calculate odd (3rd to 63rd) or all (1st to 64th) integer voltage and current
harmonics and display them as a bar diagram on the display.
It is also possible to read out the data using a Modbus command.
The Modbus table can be f
ound in chapter Readout of harmonic components of all
harmonics with function codes 0x03 and 0x04 (Page126).
Harmonics referred to the root-mean-square value
The fundamental of the voltage is speci󹪝ed in volts (V) rather than percent (%). The harmonics
of the voltage referred to the root-mean-square value (rms) can be calculated from this
information in the software.
THD
The THD (total harmonic distortion) is used to describe the distortion of the electrical signal. It
indicates the ratio of the harmonic content to the fundamental in percent.
Description
2.6Technical features of the network quality
PAC4220
30 Equipment Manual, L1V30827278B-01