Siemens Sinamics S120 Function Manual page 192

Vector control
4.18 Instructions for commissioning permanent-magnet synchronous motors
Features
● Field weakening up to approx. 1.2 * rated speed (this depends on the drive converter
● Flying restart (for operation without encoder, only possible with additional VSM)
● Vector closed-loop speed and torque control
● Vector V/f control for diagnostics
● Motor identification
● Automatic rotating encoder adjustment (the zero encoder position is calibrated)
● Speed controller optimization (rotating measurement)
● Thermal protection via temperature sensor (PTC/KTY)
● All encoders that can be connected to an SMC10, SMC20 or SMC30 are supported.
● Operation with or without encoder is possible.
Supplementary conditions
● Maximum speed or maximum torque depend on the converter output voltage available
● Calculating the maximum speed:
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.
With p0643 = 1, it must be ensured that there is sufficiently high and suitable overvoltage
protection. If necessary, system-side precautions should be taken.
190
supply voltage and the motor data, also refer to supplementary conditions)
and the back EMF of the motor (calculation specifications: EMF must not exceed U
converter).
=
=
π
Figure 4-26 Formula vector maximum speed
Calculating k see "Commissioning".
T
CAUTION
Function Manual, (FH1), 01/2012, 6SL3097-4AB00-0BP2
rated
Drive functions