● The circuit breaker is controlled and enabled from the closed-loop control. If this has not
been enabled, under no circumstances should you close the circuit breaker using external
mechanical or electrical means.
● To protect the converter transformer, ensure that overcurrent protection is in place.
3.5.10
Converter transformer
A two-winding transformer is required for each Active Line Module. When two complete drive
units are connected in parallel, a three-winding transformer with shifted windings can be used
for suppressing line harmonics.
Consider the following properties during the configuration:
● Transformer secondary voltage:
– 3.3 kV
– 4.16 kV
● Minimum leakage inductance: 1 mH
(short-circuit voltage
u
k
≥ 15% depending on transformer output)
This value includes all the inductance between the line and the converter: Line short-circuit
inductance, transformer inductance, reactor inductance.
● Transformer taps for voltage adjustments: 2 x +/- 2.5%. The winding taps are usually located
on the high voltage side of the transformer.
Design the transformer for the following loads:
● Max. dU/dt stress at the converter input terminals: 6 kV/µS
● Peak voltage load phase-phase and phase-ground:
– With 3.3 kV converters = 8.4 kV
– With 4.16 kV converters = 10.5 kV
● Current load with DC component: approx. 4 A to 5 A
3.5.11
Actual value acquisition
Actual current and voltage values are recorded by the AVT combination module
①
. The AVT
combination module converts analog signals into digital signals and forwards them to the PSA.
The signals are transferred to the PSA via fiber-optic cables.
Description
3.5 Description of the components
SINAMICS SM150 6SL3815-7NP41-0AA1
Operating Instructions Rev.201910281301 EXAMPLE
37
