Notes Regarding Pole Position Identification - Siemens SINAMICS S120 Function Manual

4.14.1

Notes regarding pole position identification

The relevant procedure can be selected using parameter P1980. The following procedures
are available for pole position identification:
● Saturation-based 1st + 2nd harmonics (p1980 = 0)
● Saturation-based 1st harmonic (p1980 = 1)
● Saturation-based, two-stage (p1980 = 4)
● Motion-based (p1980 = 10)
● Elasticity-based (p1980 = 20)
The following supplementary conditions apply to the saturation-based motion procedure:
● This procedure can be used for both braked and non-braked motors.
● It can only be used for a speed setpoint = 0 or from standstill.
● The specified current magnitudes (p0325, p0329) must be sufficient to provide a
significant measuring result.
● For motors without iron, the pole position cannot be identified using the saturation-based
procedure.
● For 1FN3 motors, it is not permissible to traverse with the 2nd harmonic (p1980 = 0, 4).
● With 1FK7 motors, a two-stage procedure must not be used (p1980 = 4). The value in
p0329, which is set automatically, must not be reduced.
For the motion-based procedure, the following supplementary conditions apply:
Note
Inaccuracy when determining the commutation angle
If several 1FN3 linear motors are coupled with one another, and at the same time saturation-
based pole position identification is used for commutation (p1980 ≤ 4 and p1982 = 1), then
this can influence the DC link voltage. Fast current changes in the DC link cannot be
completely compensated. In this case, the commutation angle is not precisely determined
using the pole position identification.
• If a high precision is required, then carry out the pole position identification routines one
after the other. This can be achieved, for example, by enabling the individual drives one
after the other (with a time offset).
● The motor must be free to move and it may not be subject to external forces (no
hanging/suspended axes).
● It can only be used for a speed setpoint = 0 or from standstill.
● If there is a motor brake, then this must be open (p1215 = 2).
● The specified current magnitude (p1993) must move the motor by a sufficient amount.
Drive functions
Function Manual, 11/2017, 6SL3097-4AB00-0BP5
Servo control
4.14 Pole position identification
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