Siemens SINAMICS S120 Function Manual page 269

3. For an induction or reluctance motor, immediately after the speed has been determined,
magnetization starts (p0346).
4. The current speed setpoint in the ramp-function generator is then set to the current actual
speed value.
The ramp-up to the final speed setpoint starts with this value.
Example
After a power failure, a fan drive can be quickly reconnected to the running fan motor by means
of the "flying restart" function.
Figure 6-23
Figure 6-24
Drive functions
Function Manual, 06/2019, 6SL3097-5AB00-0BP2
Application example: Induction motor without encoder
ON
Application example: Induction motor with encoder
Vector control
6.17 Flying restart
t
t
267