Power Factor - Danfoss VLT HVAC Basic Drive FC 101 Design Manual

Introduction
1 1
plus
VVC
Compared with standard voltage/frequency ratio control,
Voltage Vector Control (VVC
and stability, both when the speed reference is changed
and in relation to the load torque.

1.7 Power Factor

The power factor is the relation between I
3 × U × I 1 × COS ϕ
Power factor =
3 ×
The power factor for 3-phase control:
I cos ϕ1 I
×
1 1
= =
I I
RMS RMS
The power factor indicates to which 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
IRMS
= + +
In addition, a high power factor indicates that the different
harmonic currents are low.
The adjustable frequency drive's built-in DC coils produce a
high power factor, which minimizes the imposed load on
the line power supply.
8
plus
) improves the dynamics
U × IRMS
since cos ϕ1 = 1
I n 2
+ . . +
Danfoss A/S © Rev. 2014-01-14 All rights reserved.
Design Guide
and I .
1 RMS
for the
RMS
MG18C522