Danfoss FC 300 Design Manual page 10

1 How to Read this Design Guide
VT Characteristics
Variable torque characteristics used for pumps and fans.
1
plus
VVC
If compared with standard voltage/frequency ratio control, Voltage Vector Control (VVC
reference is changed and in relation to the load torque.
60° AVM
Switching pattern called 60°Asynchronous Vector Modulation (par. 14-00
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.
All Danfoss frequency converters have built-in DC coils in the DC link to have a high power factor and to reduce the THD on the main supply.
10
Switching Pattern
and I .
1 RMS
for the same kW per-
RMS
MG.33.BC.02 - VLT ®
plus ) improves the dynamics and the stability, both when the speed
).
x U x I cos
3
1
Power factor
=
x U x I RMS
3
I
I 1 x cos ϕ1 1
= = since cos
I RMS I RMS
2 + 2 + 2 + .. +
I RMS I I I
=
1 5 7
is a registered Danfoss trademark
FC 300 Design Guide
ϕ
ϕ1 = 1
2
I n