Automatic Encoder Adjustment - Siemens SINAMICS S120 Function Manual

Vector control
4.16 Instructions for commissioning permanent-magnet synchronous motors
4.16.1

Automatic encoder adjustment

Description
The pole wheel-oriented closed-loop control of the synchronous motor requires information
about the pole wheel position angle. Automatic encoder adjustment must be used if the pole
wheel position encoders are not mechanically adjusted and after a motor encoder has been
replaced.
Automatic encoder adjustment only makes sense for encoders with absolute position
information and/or zero mark. The following encoders are supported:
● Sin/Cos encoder with A/B-, R-track as well as with A/B-, C/D-, R-track
● Resolver
● Absolute encoder (e.g. EnDat, DRIVE-CLiQ encoder, SSI)
● Incremental encoder with zero mark
Encoder adjustment using a zero mark
If an incremental encoder with zero mark is being used, after the zero mark has been
passed, the position of the zero mark can be calibrated. Commutation with the zero mark is
activated via p0404.15.
Commissioning
Automatic encoder adjustment is activated with p1990 = 1. When the pulses are enabled the
next time, the measurement is carried out and the angular difference determined (p1984) is
entered into p0431. For p1990 = 2 the determined angular difference (p1984) is not entered
into p0431 and has not effect on the closed-loop motor control. Using this function, the
angular difference - entered into p0431 - can be checked. For extremely high moments of
inertia, the run time can be scaled higher using p1999.
The measurement causes the motor to rotate. The motor turns through a minimum of one
complete revolution.
Integration
Automatic encoder adjustment is integrated into the system in the following way:
Overview of important parameters (see SINAMICS S120/S150 List Manual)
● p0404.15 Commutation with zero mark
● p0431 Angular commutation offset
● p1990 Encoder adjustment selection
● p1999 Angular commutation offset calibration, scaling
164
WARNING
Function Manual, (FH1), 10/2008, 6SL3097-2AB00-0BP5
Drive functions