Siemens SINAMICS S120 - Page 67

Fundamental Principles and System Description
Engineering Information
SINAMICS Engineering Manual – November 2015
Ó Siemens AG
67/528
The fundamental power factor cosφ
1
The relation between the active power P and the fundamental apparent power S
1
is referred to as the "fundamental
power factor cosφ
1
" and is defined as follows:
2
1
2
1
1
2
1
2
1
1
cos
reactact
act
II
I
QP
P
S
P
--
-
+
=
+
==
j
.
The fundamental power factor cosφ
1
of the different SINAMICS converters and Infeeds is dependent on the line
impedance or the Relative Short-Circuit power (RSC) at the PCC (Point of Common Coupling) and on the drive load.
The following table shows the typical values of the fundamental power factor cosφ
1
for the SINAMICS converters and
Infeeds described in this engineering manual as a function of the relative short-circuit power RSC. The value for self-
commutated Infeeds (S120 Active Infeed and S150) can be parameterized in the firmware. The factory setting is "1".
Fundamental power factor cosφ
1
for line-commutated SINAMICS converters and Infeeds
SINAMICS G130, G150, S120 Basic Infeed and S120 Smart Infeed
Relative short-circuit power RSC 100 % load
> 50 (strong line supply) ≈ 0.975
15 … 50 (medium line supply) ≈ 0.970
< 15 (weak line supply) ≈ 0.960
Fundamental power factor cosφ
1
for line-commutated SINAMICS converters with LHF compact
SINAMICS G150 with option L01
Relative short-circuit power RSC 100 % load
No significant dependency on RSC ≈ 0.99 capacitive
Fundamental power factor cosφ
1
for self-commutated SINAMICS converters and Infeeds
SINAMICS S120 Active Infeed and S150 with factory setting of cosφ
1
to "1"
Relative short-circuit power RSC 100 % load
No significant dependency on RSC ≈ 1.00
Typical values of the fundamental power factor cosφ
1
for SINAMICS converters and Infeeds
The total power factor λ
The relation between the active power P and the total apparent power S is referred to as the "total power factor λ"
and is defined as follows.
å
¥=
=
--
-
++
=
++
==
h
h
hreactact
act
III
I
DQP
P
S
P
2
22
1
2
1
1
22
1
2
l .
The total power factor λ of the different SINAMICS converters and Infeeds is dependent on the line impedance or the
Relative Short-Circuit Power (RSC) at the PCC (Point of Common Coupling) and on the drive load.
Since the total power factor λ includes the distortive (reactive) power D generated by harmonic currents as well as
the fundamental reactive power Q
1
, it is always smaller than the fundamental power factor cosφ
1
in the case of line
currents with harmonic content.
The following table shows the typical values of the total power factor λ for the SINAMICS converters and Infeeds
described in this engineering manual as a function of the relative short-circuit power RSC.
The value for self-commutated Infeeds depends on the fundamental power factor cosφ
1
parameterized in the
firmware for which the factory setting is “1”.