1. Harmonics can be reduced by using of line inductances (AC-chokes) or
DC-bus- inductances. Other possibilities are active filters, high-pulse inverter
(12-pulse, 24-pulse) or special compensation circuits on the supply side or in
the frequency inverter.
If AC or DC Choke is used:
Choice criteria: inverter line current, needed uk (%), needed THD, voltage fluctuations
Critical points: additional voltage loss, size, weight
Remember, that values (limits) for voltage and current are not equal.

2. in the European Norm EN61000-3-2 and 61000-3-12
The maximum harmonic levels for public power supply networks are defined
in the European Norm EN and
Harmonic current content in % (value of the fundamental current is 100%)
Total Harmonic distortion in % up to the 40th harmonic
Hz ….

3. Harmonic current content in % (value of the fundamental current is 100%)
Table of harmonics (following data from Japanese manuals) 5th 7th 11th 13th 17th 19th 23th 25th THiD without ,5 7,7 4,3 3,1 2,6 1, with AC 38 14,5 7,4 3,4 3,2 1,9 1,7 1, with DC ,4 5,0 4,7 3,2 3,0 2, with AC+DC 28 9,1 7,2 4,1 3,2 2,4 1,6 1, Remember that table values may differ in relation to line power source. A700 and F700 beginning from power module EC DC-Reactor is included.