Pole Position Identification - Siemens SINAMICS S120 Function Manual

Servo control

5.16 Pole position identification

5.16 Pole position identification
Function description
Unplanned motor motion when carrying out measurements at motors that are not braked
The measurement for unbraked motors can cause a motor movement with the specified
current that can lead to death or severe injuries.
● Ensure that nobody is in the danger zone and that the mechanical parts can move freely.
For synchronous motors, the pole position identification (PolID) determines the electrical pole
position required for the field-oriented closed-loop control. Generally, the electrical pole
position is provided from a mechanically adjusted encoder with absolute information.
Motors with encoders that are either not calibrated or have not been adjusted require a one-off
PolID:
1. Select a technique with p1980
2. Set the value "1" in parameter p1990 to start the selected technique.
The value in p1982 is not taken into account.
Absolute encoders are automatically identified when commissioning or after an encoder has
been replaced based on the saved serial number. As a consequence, for Siemens linear
motors 1FN1, 1FN3 and 1FN6, p1990 = 1 is automatically set after commissioning or after an
encoder has been replaced.
Incremental encoders are not automatically identified as they have no serial number. As a
consequence, after commissioning, or after an encoder has been replaced, a value of "1" is not
automatically set in p1990, and must be additionally entered.
A PolID is not required for the following encoder properties:
● Absolute encoder (e.g. EnDat, DRIVE-CLiQ encoder)
● Encoder with C/D track and pole pair number ≤ 8
● Hall sensor
● Resolver with a multiple integer ratio between the motor pole pair number and the encoder
pole pair number
● Incremental encoder with a multiple integer ratio between the motor pole pair number and
the encoder pulse number
The PolID is used for:
● Determining the pole position (p1982 = 1)
● Determining the commutation angle offset during commissioning (p1990 = 1)
● Plausibility check for encoders with absolute information (p1982 = 2)
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WARNING
Function Manual, 06/2019, 6SL3097-5AB00-0BP2
Drive functions