Active Infeed - Siemens SINAMICS G130 Engineering Manual

Fundamental Principles and System Description
Engineering Information

Active Infeed

The Active Infeed is an actively pulsed, regulated rectifier / regenerative unit for four-quadrant operation (i.e. energy
flows from the supply system to the DC link and vice versa).
The Active Infeed comprises a self-commutated IGBT inverter (Active Line Module ALM), which operates on the
supply system via the Clean Power Filter (Active Interface Module). The Active Line Module operates according to
the method of pulse-width modulation and generates a constant, regulated DC link voltage V
line voltage V . The Clean Power Filter, which is installed between the Active Line Module and the supply system,
Line
filters out, as far as possible, the harmonics from the Active Line Module's pulse-width-modulated voltage V
thereby ensuring a virtually sinusoidal input current on the line side and, therefore, minimal harmonic effects on the
supply system.
The Active Infeed is the highest grade SINAMICS infeed variant. It is a component of SINAMICS S150 cabinet units
and is available as a stand-alone infeed of the SINAMICS S120 modular system, in Chassis and Cabinet Modules
format.
SINAMICS S120 Active Infeed comprising an Active Interface Module and an Active Line Module
The Active Infeed is a self-commutated rectifier / regenerative unit and produces from the three-phase line voltage
V a regulated DC link voltage V
Line
supply voltage dips. It operates as a step-up converter, i.e. the DC link voltage is always higher than the peak value
of the line voltage (V
DCLink
This setting should not be changed without a valid reason. Reducing the factory-set value tends to impair the control
quality while increasing it unnecessarily increases the voltage on the inverter and the motor winding. If the
permissible voltage of the motor winding is sufficiently high (see section "Increased voltage stress on the motor
winding as a result of long cables"), the DC link voltage can be increased from the factory setting to the values
V specified in the table. This method allows a voltage higher than the line voltage to be obtained at the output of
DCmax
the inverter or Motor Module connected to the Active Infeed. The table shows the maximum achievable inverter
output voltage as a function of the DC link voltage and the modulation system used for vector control (space vector
modulation SVM or pulse-edge modulation PEM).
Supply voltage
V
Line
Units with 380 V – 480 V 3AC
Units with 500 V – 690 V 3AC
in operation with supply voltages
500 V – 600 V 3AC
660 V – 690 V 3AC
SINAMICS Active Infeed: Maximum, continuously permissible DC link voltages and attainable output voltages
As the magnitude of the DC link voltage can be parameterized and the DC link current depends on this parameter
setting, the DC current is not suitable as a criterion for dimensioning the Active Infeed required. For this reason, the
power balance of the drive should always be used as a basis for dimensioning the Active Infeed.
SINAMICS Engineering Manual – May 2008
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© Siemens AG
which remains constant independently from line voltage variations and
DCLink,
> 1.41 • V ). The value can be parameterized. The factory setting is
Line
V = 1.50 • V
DCLink
Maximum permissible DC
link voltage in steady-state
operation
V
DC max.
720 V
910 V
1100 V
Line
Maximum attainable
output voltage with
space vector
modulation
V
out max SVM
503 V
636 V
770 V
from the three-phase
DC
,
ALM
Maximum attainable
output voltage with
pulse-edge modulation
V
out max. PEM
538 V
680 V
822 V