Harmonic Currents And Harmonic Voltages Of Active Infeeds (Afe Technology) - Siemens SINAMICS G130 Engineering Manual

However, as in practice there is never a perfectly symmetrical load distribution between the two rectifiers, it must be
assumed that harmonic currents with harmonic numbers h = 5, 7, 17, 19, 29, 31, 41, 43, ...... are also present with
12-pulse circuits, but with amplitudes that are maximum 10 % of the corresponding values of 6-pulse circuits.
The typical harmonic currents of 12-pulse rectifier circuits are specified below:
As these are generally only used with high-power ratings, it can be assumed that converters with a 12-pulse rectifier
circuit are operated on a separate three-winding transformer and line reactors are dispensed with. This constellation
corresponds to a supply system with a low to medium relative short-circuit power RSC = 15 to 25.
Supply system with low to medium relative short-circuit power (RSC = 15 ... 25): "Weak supply system"
h 1 5
I 100 % 3.7 %
h
Harmonic currents of 12-pulse rectifier circuits with separate three-winding transformer without line reactor
100
90
80
70
60
50
40
30
20
10
0
1 3 5 7
Spectral representation of the harmonic currents of 12-pulse rectifier circuits
without line reactor (specified in %)

Harmonic currents and harmonic voltages of Active Infeeds (AFE technology)

The SINAMICS Active Infeed is a self-commutated, PWM IGBT inverter (Active Line Module ALM) which produces a
constant, stabilized DC link voltage from the three-phase line voltage. Thanks to the Clean Power Filter (Active
Interface Module AIM) installed between the power supply and IGBT inverter, the power drawn from the supply is
near-to-perfect sinusoidal. The Active Infeed is ideally suited for 4Q operation, i.e. it has both Infeed and regenerative
feedback capability.
The Active Infeed is the highest grade Infeed variant for SINAMICS. It is used in SINAMICS S150 cabinets and as
S120 Active Infeed.
Active Infeed (PWM IGBT inverter with Clean Power Filter) on a three-phase supply system
Fundamental Principles and System Description
7 11
1.2 % 6.9 %
9 11 13 15 17 19 21 23 25
13 17 19
3.2 % 0.3 % 0.2 %
SINAMICS Engineering Manual - May 2008
Engineering Information
23 25
1.4 % 1.3 %
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© Siemens AG
THD(I)
8.8 %