Lenze Inverter EMC - Manual (Page 17)

Limiting harmonic currents in the supply mains
15
l
EDBEMV EN 1.3
7 Limiting harmonic currents in the supply
mains
Power consumption of a standard inverter
The input circuit of a frequency inverter with DC voltage bus generally consists of an uncontrolled
rectifier and the DC bus capacitance made up of electrolytic capacitors.
Single-phase bridge-connected rectifier without choke Single-phase bridge-connected rectifier with choke
ohne Dross el
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m it Dros sel
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Non-sinusoidal input currents of frequency inverters are referred to as harmonic currents (mains
harmonics) and can ” pollute” the supply system and have an impact on other consumers.
European Standard EN 61000-3-2 ensures the quality of public mains systems, specifying limit
values to restrict mains loads (background: increasing number of non-linear consumers).
The standard only applies to public mains systems. Mains systems which have their own
transformer station as common in industry are not public. The standard does not apply to them.
This affects units (inverters) with an input current (mains current) of up to 16 A or with input powers
of up to 1 kW.
If a machine or system consists of several components, the limit values apply to the entire machine
or system.
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