Siemens Sinamics s120 Commissioning Manual page 228

Commissioning
3.16 Commissioning permanent-magnet synchronous motors
Supplementary conditions
● Maximum speed or maximum torque depend on the converter output voltage available
and the back EMF of the motor (calculation specifications: EMF must not exceed U
converter).
● Calculating the maximum speed:
Image 3-70
Calculating k
Note
If pulse inhibition of the converter occurs (fault or OFF2), synchronous motors can
generate high terminal voltages in the field-weakening range, which could lead to
overvoltage in the DC link. The following possibilities exist to protect the drive system
from being destroyed due to overvoltage:
1. Restrict (p0643 = 0) maximum speed (p1082)
2. External voltage limiter or chopper or other measures appropriate to the application.
● Depending on the terminal voltage and load cycle, the maximum torque can be taken
from the motor data sheets / configuration instructions.
228
Formula vector maximum speed
see "Commissioning".
T
WARNING
Dangerous overvoltage
With p0643 = 1, it must be ensured that there is sufficiently high and suitable
overvoltage protection. If necessary, system-side precautions should be taken.
Do not enter the working area of the motor.
STARTER Commissioning Manual
Commissioning Manual, (IH1), 07/2016, 6SL3097-4AF00-0BP5
rated