Siemens SINAMICS GL150, Operating Instructions Manual

Page: 33 / 168

Components of the thyristor stack
Each thyristor is connected with a resistor and a capacitor. The resistor and capacitor have the
following tasks:
● Where there are several thyristors in series, the resistor and capacitor split up the supply
voltage equally.
● If the thyristors are switched off, the resistor and capacitor limit the rate of voltage rise and
voltage overshoot.
A thyristor electronics module is assigned to each thyristor. The thyristor electronics are used
to fire the thyristors. The thyristor electronics are supplied with energy from the RC circuit.
See also
Thyristor electronics (Page 40)
3.3.2.2 DC-link reactor
The DC link reactor decouples the line-side converter from the motor-side converter and
smoothes the direct current. In the event of a fault with overcurrent, the DC link reactor limits the
rate of current rise with its inductance, together with the line reactors. Each DC link reactor
consists of two magnetically coupled windings wound on an iron core.
3.3.2.3 dI/dt reactor
dI/dt reactors (ring cores) are integrated in the connecting busbars on the line and motor sides.
They limit the rate of current rise when the system capacitance is discharged.
,
5 5
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Figure 3-3 Saturable reactor
The number of cores in the module depends on the following factors:
● Supply voltage
● System capacitance
● RC circuits
● The firing angle range in which the converter is operated
3.3.2.4 AVT combination module
The AVT combination module (Actual Value Transmission) processes signals for sensing the
actual current and voltage values. The AVT combination module converts analog signals into
digital signals. Then the module transfers the signals to the Power Stack Adapter (PSA). The
signals are transferred to the PSA via fiber-optic cables.
Description
3.3 Power unit
SINAMICS GL150 6SL38555UN113KA0Z
Operating Instructions Rev.201910281450 EXAMPLE
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