Explanations Of The Characteristic Curves - Siemens SIMOTICS T-1FW6 Configuration Manual

7.1.2

Explanations of the characteristic curves

Torque-speed diagram with field weakening
1 S1 duty
2 S1 duty with field weakening
3 S3 duty, cycle duration should not exceed 10% of the thermal time constant t
4 S3 duty with field weakening, cycle duration should not exceed 10% of the thermal time constant t
5 Voltage limit characteristic
6 Limit characteristic for S1 duty
7 Voltage limit characteristic with field weakening
8 Rated operating point at M
9 Operating point at M
10 Torque M at speed n = 1 r/min
0
Figure 7-5 Schematic description of the torque-speed diagram
The voltage induced in the motor winding increases as the speed increases. The difference
between the DC link voltage of the converter and the induced motor voltage can be used to
impress the current.
The torque must be reduced if the voltage limit of the infeed module is reached at speed n.
All operating points that can be achieved with the motor lie below the "voltage limiting
characteristic".
For the SINAMICS S120 drive system, as a result of the field weakening function, when the
"voltage limiting characteristic" is reached, then the voltage induced in the motor winding is
automatically compensated. As a consequence, the speed range of a motor can be extended
without requiring a larger power module. The operating points for field weakening that
1FW6 Built-in torque motors
Configuration Manual, 09/2022, A5E52220645B AA
, n , I
N N N
, I , n
MAX MAX MAX,MMAX
Technical data and characteristics
7.1 Explanations
TH
TH
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