Siemens SINAMICS G130 Engineering Manual page 481

Overload and overtemperature protection
SINAMICS S150 converter cabinets are equipped with effective overload and overtemperature protection
mechanisms which protect them against thermal overloading.
Sensors at various locations in the converter (inlet air, control electronics, rectifier heatsink, inverter heatsink)
measure the relevant temperatures and feed them into the so-called "Thermal model". This continuously calculates
the temperature at critical positions on power components. In this way the converter is effectively protected against
thermal overloads, whether they are caused by excessive current or high ambient temperatures. The so-called "I
monitoring circuit" checks the level of utilization of the motor-side inverter. If the level of inverter utilization or the
temperature at any point in the converter exceeds the upper tolerance limit, the converter responds by initiating an
overload reaction parameterized in the firmware. It is possible to select whether the converter should react to
overload by reducing the output frequency and output current or the pulse frequency. Immediate shutdown can also
be parameterized.
Maximum output frequency
With SINAMICS S150 cabinet units, the maximum output frequency is limited to 100 Hz or 160 Hz due to the factory-
set pulse frequency of f
Pulse
clock cycle = 250 μs). The pulse frequency must be increased if higher output frequencies are to be achieved. Since
the switching losses in the motor-side IGBT inverter increase when the pulse frequency is raised, the output current
must be reduced accordingly.
Permissible output current and maximum output frequency as a function of pulse frequency
The table below states the rated output currents of SINAMICS S150 converters with the factory-set pulse frequency,
as well as the current derating factors (permissible output currents referred to the rated output current) at higher
pulse frequencies.
The pulse frequencies for the values in the orange boxes can be selected simply by changing a parameter (even
during operation), i.e. they do not necessitate a change to the factory-set current controller clock cycle. The pulse
frequencies for the values in the grey boxes require a change in the factory-set current controller clock cycle and can
therefore be selected only at the commissioning stage. The assignment between current controller clock cycles and
possible pulse frequencies can be found in the List Manual (Parameter List).
Under certain boundary conditions (line voltage at low end of permissible wide-voltage range, low ambient
temperature, restricted speed range), it is possible to partially or completely dispense with current derating at pulse
frequencies which are twice as high as the factory setting. Further details can be found in section "Operation of
converters at increased pulse frequency".
Rated output current
Output power
at current derating factor
400 V with pulse frequency of
1.25 kHz
380 V – 480 V 3AC
110 kW
132 kW
160 kW
200 kW
250 kW
315 kW 605 A
400 kW 745 A
450 kW 840 A
560 kW 985 A
710 kW 1260 A
800 kW 1405 A
SINAMICS S150: Permissible output current (current derating factor) as a function of pulse frequency
= 1.25 kHz (current controller clock cycle = 400 μs) or f
or
2.0 kHz 2.5 kHz
210 A 95 %
260 A 95 %
310 A 97 %
380 A 96 %
490 A 94 %
83 % 72 %
83 % 72 %
87 % 79 %
92 % 87 %
92 % 87 %
97 % 95 %
Engineering Information
Current derating factor
with pulse frequency of
4.0 kHz 5.0 kHz
82 % 74 %
83 % 74 %
88 % 78 %
87 % 77 %
78 % 71 %
64 % 60 %
64 % 60 %
64 % 55 %
70 % 60 %
70 % 60 %
74 % 60 %
SINAMICS Engineering Manual – November 2015
SINAMICS S150
= 2.00 kHz (current controller
Pulse
7.5 kHz 8.0 kHz
54 % 50 %
54 % 50 %
54 % 50 %
54 % 50 %
53 % 50 %
40 %
40 %
40 %
50 %
50 %
50 %
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