Line Reactors - Siemens SINAMICS G130 Engineering Manual

SINAMICS S120 Cabinet Modules
Engineering Information

Line reactors

Line reactors are used in conjunction with Basic Line Modules or Smart Line Modules.
A line reactor must be installed whenever
•
the rectifiers are connected to a line supply system with high short-circuit power, i.e. with low line supply
inductance
•
more than one rectifier is connected to the same point of common coupling (PCC),
•
the rectifiers are equipped with line filters for RFI suppression filters
•
rectifiers are operating in parallel to achieve a higher output power.
The line reactor smoothes the current drawn by the rectifier, thereby reducing harmonic components in the line
current and thus the thermal load on the DC link capacitors of the rectifier. The harmonic effects on the supply are
also reduced, i.e. both the harmonic currents and harmonic voltages in the power supply are attenuated.
Line reactors can be dispensed with only if the supply cable inductance is sufficiently high or the relative short-circuit
*)
power RSC correspondingly low.
The following values apply to Basic Line Modules:
Output power Line reactor can be omitted
kW for an RSC of
<200
200 to 500
>500
With Smart Line Modules the use of line reactors is generally necessary. Therefore line reactors are included as a
standard and cannot be omitted.
With Basic Line Modules operating in parallel connection on a common Line Connection Module, line reactors must
always be used.
As the configuration of the supply system for operating individual Basic Line Modules is often not known in practice,
i.e. the short-circuit power at the PCC of the modules is not certain, it is advisable to connect a line reactor on the line
side in cases of doubt.
A line reactor can only be dispensed with when the RSC value for relative short-circuit power is less than stated in
the above table. For example, this applies if, as illustrated in the diagram below, the Basic Line Module is connected
to the supply via a transformer with specially adapted rating and none of the other reasons stated above for using a
line reactor is valid.
*)
RSC = Relative short-circuit power:
Ratio of the short-circuit power S
converters (according to EN 50 178 / VDE 0160).
SINAMICS Engineering Manual – May 2008
254/396
© Siemens AG
Option Code
≤ 43
L22
≤ 33
L22
≤ 20
L22
at the PCC to the fundamental frequency apparent power S
k line
Line reactor required
for an RSC of
> 43
> 33
> 20
Converter
of the connected