Danfoss VLT HVAC Drive FC 102 Design Manual page 15

How to Read this Design Gui...
VT Characteristics
Variable torque characteristics used for pumps and fans.
plus
VVC
Compared with standard voltage/frequency ratio control,
Voltage Vector Control (VVC plus
and stability, both when the speed reference is changed
and in relation to the load torque.
60° AVM
Switching pattern called 60°Asynchronous Vector
Modulation (See 14-00 Switching Pattern).
The power factor is the relation between I
3 × U × I 1 × COS ϕ
Power factor =
3 × U × IRMS
The power factor for 3-phase control:
I cos ϕ1 I
×
1 1
= = since cos ϕ1 = 1
I I
RMS RMS
The power factor indicates to what extent the adjustable
frequency drive imposes a load on the line power supply.
The lower the power factor, the higher the I
same kW performance.
I 1 2 I 5 2 I 7 2 I n 2
IRMS
= + + + . . +
In addition, a high power factor indicates that the different
harmonic currents are low.
The built-in DC coils produce a high power factor, which
minimizes the imposed load on the line power supply.
MG16C122
Design Guide
) improves the dynamics
and I .
1 RMS
for the
RMS
Danfoss A/S © Rev. 2014-01-13 All rights reserved.
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