Danfoss VLT AQUA Design Manual page 9

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VLT AQUA Drive Design Guide
1.1.6. Power Factor
The power factor is the relation between I
The power factor for 3-phase control:
The power factor indicates to which extent the frequency converter im-
poses a load on the mains supply.
The lower the power factor, the higher the I
formance.
In addition, a high power factor indicates that the different harmonic currents are low.
The frequency converters' built-in DC coils produce a high power factor, which minimises the imposed load on the mains supply.
and I .
1 RMS
for the same kW per-
RMS
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MG.20.N3.02 - VLT is a registered Danfoss trademark
1. How to Read this Design Guide
U
3 × ×
Power factor
=
3 × U
I cos I
1 × ϕ1
1
since cos
= =
I RMS I RMS
2 2 2
I RMS I I I
= + + + . . +
1 5 7
I
COS
1 × ϕ
× I RMS
ϕ1 = 1
2
I
n
1
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