Siemens 6SL38503UM114PA0Z, Operating Instructions & Installation Instructions

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3.5.2 Damping switch for 1.4 kV (option C50)
The damping circuit includes a rectifier circuit with RC circuit. The damping circuit is connected
to the output of the starting converter. As a result, oscillations that are caused by cable
capacitance and leakage inductances of the generator and main transformer are attenuated.
The damping circuit is installed in the reactor cabinet above the DC link reactor.
The damping circuit is required for compact excitation systems, for which there is no generator
switch. In cases such as these, a block transformer is connected in parallel to the generator on
whose primary side cables are still connected. This arrangement forms an oscillating circuit
with a natural frequency in the order of magnitude of 1 kHz. The damping circuit dampens the
oscillations to such an extent that no premature zero crossings of the voltage on the thyristor
occur after the thyristor has been switched off.
3.5.3 Duty cycle (option C61)
The starting frequency converter is dimensioned in such a way that the specified duty cycles
can be performed. The duty cycles are possible with the described operating modes without
thermal overload at maximum ambient temperature.
The gas turbine is started in the "normal start" operating mode. The gas turbine is partly started
with upstream ventilation of the exhaust gas section and the boiler.
Operating mode Power of the starting frequency
converter (SFC)
Load cycle
% of the SFC nominal power or
current at U
g
< U
n
-SFC
Operating time (min)
Ventilation 70 0
Pause 0 0
1. Normal start 100 4
Pause 0 2.5
Ventilation 70 0
Pause 0 0
2. Normal start 100 4
Pause 0 2.5
Ventilation 70 0
Pause 0 0
3. Normal start 100 4
Pause 0 2.5
Ventilation 70 0
Pause 0 0
4. Normal start 100 4
Non-operational period 0 120
It can be derived from the load cycles that the starting frequency converter is not dimensioned
for continuous operation at nominal power.
Description
3.5 Options
SINAMICS GL150 6SL38503UM114PA0Z
42
Operating Instructions Rev.201910301420 MUSTER