Siemens SINAMICS S120 Function Manual page 593

Making the settings
The following parameter settings are important when filling the compensation tables:
Parame‐ Bit Index
ter
p5251 0 ‑
1 ‑
0.1 ‑
2 ‑
p5252 - ‑
p5253 - ‑
Drive functions
Function Manual, 06/2019, 6SL3097-5AB00-0BP2
Value Meaning
1 Activate the option "New slow learning" By activating the option, the corresponding
compensation table is deleted with the learning process. During the learning proc‐
ess, the cogging torque compensation is automatically deactivated.
So that the acceleration torque does not distort the results, this option may only be
activated after the normal speed is reached.
With slow learning, the motor must be operated at a very low speed (1.5
velocity (0.1 m/min). During the learning run, the cogging torque can be measured
when moving the motor and stored in the table.
Additional values are averaged when passing through several periods. The number
of average periods can be viewed in r5254[0], the actual table index in r5254[1]. The
table is only completely filled when r5254[0] ≥ 2.
1 Activate the option "Supplementary slow learning". This setting is used to fill the
compensation table in several steps across multiple learning processes. This is
required, for example, with a linear motor. During the learning process, the cogging
torque compensation is automatically deactivated. This supplementary learning
is only possible for non-direction-based cogging torque compensation (p5250.1 =
0).
During supplementary learning, gaps in the table are filled in. Where there were
previously already values in the table and new values are measured due to over‐
lapping, an average is used (old value/new value).
An overlap is necessary for supplementary learning. Without overlaps, the values of
the supplementary learning are rejected and only the values of the first learning
process remain.
0 Shuts down the slow learning. Following this, the mean value of the measured
values in the table is determined and removed.
1 Removes the mean value of a compensation table. This setting is required if com‐
pensation values calculated through learning must be manually corrected at the
start/end of the compensation table. The values in the table to be corrected must be
deleted from the range at the edge of the table!
n Used to define the length of a compensation table. When specifying the length, only
powers of two are permitted (2
motor), at least 10 compensation values are required for each pole.
● Example: linear motor: p0315 = 30 mm, traversing distance = 1500 mm. As a
consequence, this results in p5252 ≥ 1024 values.
n Sets the factor for the search velocity for the periodicity during cogging torque com‐
pensation.
● For rotating motors, the factor refers to one mechanical revolution (p5253 = 0.5
then generates one period of half of one mechanical revolution).
● For linear motors, the factor refers to one pole pair width.
● For synchronous motors, you should select the complete traversing range as
period (i.e. p5253 = traversing distance [mm] / p0315). The motor measuring
system must have absolute information here, which is unique regarding the
period; whereby an overflow in the actual value representation can destroy this
uniqueness.
9.15 Cogging torque compensation
). To achieve a sensible compensation (for linear
p5252
Function modules
) or
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