Siemens SINAMICS S120 Function Manual page 160

Servo control
4.14 Pole position identification
For the elasticity-based procedure, the following supplementary conditions apply:
● A brake must be available and must also be closed during the pole position identification.
Either the drive controls the brake (p1215 = 1 or 3) or the brake is externally closed well
in advance of the start of the pole position identification and is re-opened after the
operation has been completed.
● Parameters p3090 to p3096 must be correctly set for a successful pole position
identification.
● The specified current magnitude (p3096) must deflect the motor by a sufficient amount.
● The ratio between the sign of the deflection and the force/torque must be taken into
account in p3090.0.
Uncontrolled motor motion as a result of an incorrect control sense of the speed control
loop
If, to determine the commutation angle, the pole position identification routine is used, then
the commutation angle must redetermined each time that the control sense is changed. An
incorrect commutation angle can lead to uncontrollable motor movement - and therefore
result in death or severe injury.
• Check the commutation angle offset (F7966) after an actual value inversion, and when
Pole position correction with zero marks
The pole position identification routine provides coarse synchronization. If zero marks exist,
the pole position can be automatically compared with the zero mark position once the zero
mark(s) have been passed (fine synchronization). The zero mark position must be either
mechanically or electrically (p0431) calibrated. If the encoder system permits this, then we
recommend fine synchronization (p0404.15 = 1). This is because it avoids measurement
spread and allows the determined pole position to be additionally checked.
Suitable zero marks
● One zero mark in the complete traversing range
● Equidistant zero marks
● Distance-coded zero marks
160
WARNING
necessary redetermine the offset (p1990 = 1).
Function Manual, 11/2017, 6SL3097-4AB00-0BP5
Drive functions