SIEMENS
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Siemens D 35 · 2017
4
SINAMICS G120P built-in and wall-mounted units
PM330 Power Modules, 160 kW to 630 kW
Line reactors
■
Overview
Line reactor
A line reactor is needed for high short-circuit power levels, partly
to protect the actual converter against excessive harmonic
currents, and thus against overload, and partly to limit line har-
monics to the permitted values. The harmonic currents are lim-
ited by the total inductance comprising the line reactor and
mains supply cable inductance. Line reactors can be omitted if
the mains supply cable inductance is increased sufficiently,
i.e., the value of R
SC
must be sufficiently small.
R
SC
= Relative Short-Circuit power: Ratio of short-circuit power
S
k Line
at the supply connection point to the fundamental appar-
ent power
S
conv
of the connected converters (to IEC 60146-1-1).
PM330 Power Module requirements:
It is recommended that a line reactor is always connected on the
line side of the converter, as in practice, it is often not known on
which supply configuration individual converters are to be
operated, i.e. which supply short-circuit power is present at the
converter connection point.
A line reactor can only be dispensed with when the value for R
SC
is less than that in the above table. This is the case, when the
converter, as shown in the following figure, is connected to the
line through a transformer with the appropriate rating.
Notice:
A line reactor is always needed if a line filter is used.
In this case, the line short-circuit power
S
k1
at the connection
point of the converter is approximately:
S
k1
=
S
transf
/(
u
k transf
+
S
transf
/
S
k2 line
)
S
transf
= Transformer rated power
S
K2 line
= Short-circuit power of the higher-level voltage level
u
k transf
= Relative short-circuit voltage
Connection point of the
converter
Mains supply cable
inductance
Converter
Line reactor
Line
S
k line
G_D011_EN_00023c
Power
Line reactor can be omitted
Line reactor required
kW
for R
SC
for R
SC
<200
≤
43
>43
200 ... 500
≤
33
>33
>500
≤
20
>20
u
Connection point of the
transformer
Connection point of the
converter
Mains supply cable
inductance
Converter
S
transf
k transf
%
Line
k1
k2 line
G_D011_EN_00022c
S
S
© Siemens AG 2017