Line Harmonics Filters; Line Filters - Siemens SINAMICS G130 Engineering Manual

SINAMICS G150
Engineering Information
A line reactor can only be dispensed with (option L22) when the RSC value for relative short-circuit power is less than
stated in the above table. This applies, for example, if the converter 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.
In this case, the short-circuit power S
S
Transf
=
S
k 1
S
Transf
+
v
k Transf
S
k 2 Line
Abbreviation Meaning
S Rated apparent power of the transformer
Transf
v Relative short-circuit voltage of the transformer
k Transf
S Short-circuit power of the higher voltage level
k2 Line
As high-output converters are usually connected to medium-voltage networks via transformers to reduce their
harmonic effects on the supply, cabinet units over 500 kW are not equipped with line reactors as standard. A line
reactor (option L23) is required for cabinet units with outputs > 500 kW only if the RSC ratio is > 20.
Line reactors must always be provided if more than one converter is connected to the same point of common
coupling. In this case, the reactors perform two functions, i.e. they smooth the line current and decouple the rectifiers
at the line side. This decoupling is essential in ensuring fault-free operation of the rectifier circuit. For this reason,
each converter must be provided with its own line reactor, i.e. it is not permissible for more than one converter to be
connected to the same line reactor.
A line reactor must also be installed for any converter that is to be equipped with a line filter for RI suppression
(option L00) or with a Line Harmonics Filter (LHF) for reducing harmonic effects on the supply. This is because filters
of this type cannot be 100% effective without a line reactor (does not apply to Line Harmonics Filter LHF compact
(option L01)).
Another constellation which requires the use of line reactors is the parallel connection of converters where the
paralleled rectifiers are connected to a common power supply point. This applies to parallel connections of G150
units which use a 6-pulse connection. Option L23 is therefore required in this case. The line reactors provide for
balanced current distribution and thus ensure that no individual rectifier is overloaded by excessive current
imbalances.
5.6.3

Line Harmonics Filters

Line Harmonics Filters reduce the low-frequency harmonic effects on the supply system created by the converter to
levels which could otherwise only be achieved with 12-pulse rectifiers, allowing compliance with the strict limit values
defined in standard IEEE 519.
Further information about the operating principle of the filters and applicable supplementary conditions can be found
in section "Line Harmonics Filters (LHF and LHF compact)" in chapter "Fundamental Principles and System
Description".
5.6.4

Line filters

SINAMICS G150 converter cabinet units are equipped as standard with an integrated line filter for limiting conducted
interference emissions in accordance with EMC product standard EN 61800-3, category C3, for motor cable lengths
of up to 100 m (applications in industrial areas or in the "second" environment).
An optional line filter is also available as option L00 which renders the units with motor cable lengths up to 100 m
suitable for category C2 applications in accordance with product standard EN 61800-3 (installation in residential
areas or in the "first" environment).
SINAMICS Engineering Manual – November 2015
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Ó Siemens AG
at the PCC of the converter is approximately
k1