Power Factor - Danfoss VLT AHF005 Design Manual

Introduction to Advanced Ha...
25
20
15
10
5
0
0 20 40
Load [%]
Illustration 4.1 AHF005
60
50
40
30
20
10
0
0 20 40
Load [%]
Illustration 4.2 AHF010
Performance at 10% THvD has not been plotted. However,
the filters have been tested and can operate at 10% THvD
but the filter performance can no longer be guaranteed.
The filter performance also deteriorates with the unbalance
of the supply. Typical performance is shown in the graphs
below.
14
12
10
8
6
4
2
0
0 20 40
Load [%]
Illustration 4.3 AHF005
25
20
15
10
5
0
0 20 40
Load [%]
Illustration 4.4 AHF010
AHF005/010 Design Guide
THvD 0%
THvD 2%
THvD 5%
60 80 100
THvD 0%
THvD 2%
THvD 5%
60 80 100
0% unbalance
1% unbalance
2% unbalance
3% unbalance
60 80 100
0% unbalance
1% unbalance
2% unbalance
3% unbalance
60 80 100
®
MG.80.C4.02 - VLT is a registered Danfoss trademark

4.1.1 Power Factor

In no load conditions (the frequency converter is in stand-by)
the frequency converter current is negligible and the main
current drawn from the grid is the current through the
capacitors in the harmonic filter. Therefore the power factor
is close to 0, capacitive. The capacitive current is approxi-
mately 25% of the filter nominal current (depends on filter
size, typical values between 20 and 25%). The power factor
increases with the load. Because of the higher value of the
main inductor L in the AHF005, the power factor is slightly
0
higher than in the AHF010.
Following graphs show typical values for the true power
factor on AHF010 and AHF005.
1
0,9
0,8
0,7
0,6
0,5
0,4
0,3
0,2
0,1
0
0 20 40
Load [%]
Illustration 4.5 AHF005
1
0,9
0,8
0,7
0,6
0,5
0,4
0,3
0,2
0,1
0
0 20 40
Load [%]
Illustration 4.6 AHF010
60 80 100
60 80 100
13
4 4