Siemens SINAMICS G120D Operating Instructions Manual page 132

Setting functions
8.5 Motor control
The converter increases its output voltage – also above the motor rated speed up to the
maximum output voltage. The higher the line voltage, the greater the maximum converter
output voltage.
If the converter has reached its maximum output voltage, then it can only increase its output
frequency. From this point onwards, the motor is operated in field weakening; this means
that the available torque linearly decreases with increasing speed.
The value of the output voltage at the rated motor frequency also depends on the following
variables:
● Ratio between the converter size and the motor size
● Line voltage
● Line impedance
● Actual motor torque
The maximum possible output voltage as a function of the input voltage is provided in the
technical data, also see Section Technical data (Page 253).
132
Converter with control units CU240D-2
Operating Instructions, 04/2014, FW V4.7, A5E34262100B AA