Work during braking operation, the motor-side converter (MSR) as rectifiers and the line-side
converters as inverters. In the event of a fault during braking, the two motor-side converters
immediately switched over to inverter operation. The current in the DC link is suppressed as a
result. After that, the circuit breaker is opened.
The leakage reactances of the line transformer or the machine and the supply line from the
feeding supply system limit overcurrent in the event of internal short-circuits. In this case, the
circuit breaker responds sufficiently quickly to prevent consequential damage.
If there are control errors on the machine side, serious damage to the converter may occur. The
short-circuit current is limited by the machine reactances. On designs with output transformers,
the short-circuit current is limited by the machine reactance and the transformer reactance (uk).
Subsequent faults can be limited by independent disconnecting elements between the
converter and the motor. This is not included in the scope of supply.
The thermal utilization of the semiconductors is selected so that, after a short-circuit current, the
thyristors still have sufficient blocking ability in accordance with the figure shown below, "Short-
circuiting sequence".
The converter can cope with virtually any incident using the fuseless technology and will switch
itself off.
W
X
N
L
N
8L
6KRUWHGFLUFXLW
Figure 3-5
Short-circuiting sequence
3.3.2.2
Thyristor electronics
Gate control and monitoring system
The thyristor electronics consist of the TAS CPLD module (thyristor control and protection,
complex programmable logic device).
The thyristor electronics are part of the thyristor control and monitoring system. They work
together with the Power Stack Adapter (PSA). The thyristor electronics can control all line-side
and motor-side converters which are supplied with voltage by the gate current of the thyristor
RC circuit.
The thyristor electronics module has the following tasks:
● They generate the gate pulses for the thyristors.
● Report information on the thyristor status, the thyristor electronics themselves, and the fiber-
optic cable connection to the Power Stack Adapter.
A thyristor electronics module is assigned to each thyristor.
Description
3.3 Power unit
SINAMICS GL150 6SL38502UM114PA0Z
34
Operating Instructions Rev.201910281441 EXAMPLE
