Fast Flying Restart - Siemens SINAMICS S120 Function Manual

Flying restart in encoderless operation for long cables
As a rule, it is important to consider the cable resistance. The cable resistance is required for
calculation of the thermal motor model.
1. Enter the cable resistance in parameter p0352 before you perform motor data
identification.
2. For an induction motor, set parameter p1203[0...n] to at least 300%.
This operation can take a little longer than for the factory setting (100%).
The setting is not required for a reluctance motor.
Note
Use a trace recording to check and optimize the flying restart function. If necessary, optimize
the settings of parameters p1202 and p1203.
5.17.1

Fast flying restart

For encoderless operation (vector, V/f linear and parabolic), there is a "fast flying restart".
The "fast flying restart" function is only possible for induction motors.
Fast flying restart without voltage measurement
For fast flying restart without voltage measurement, the starting frequency is set to zero. The
model settles within approximately 200 ms on its own when the parameterization is correct.
This fast flying restart works only under the following conditions:
● At a current controller cycle time of 250 μs or 400 μs (without filter and long cables)
● Up to 4x the rated speed for vector control
● Up to the rated speed for V/f control
The settings for fast flying restart can be made in the expert list.
1. To switch flying restart to "fast flying restart", make the following setting: "p1780.11 = 1".
The normal flying restart had the parameter setting "p1780.11 = 0". For operation with
encoder, settings of this bit are ignored because fast flying restart is not possible in this
case.
2. Activate the fast flying restart as with the normal flying restart via parameter p1200.
3. Perform a standstill measurement (p1900 = 2) for the correct parameterization of the
voltage model for both vector and V/f control to determine the power resistance.
The critical parameters are the stator resistance (p0350) and the stator leakage
inductance (p0356).
The following status bits indicate the characteristic of the flying restart:
– For V/f control: r1204.14.
– For vector control: r1205.16 or r1205.17.
Drive functions
Function Manual, 11/2017, 6SL3097-4AB00-0BP5
Vector control
5.17 Flying restart
273