Siemens SINAMICS G120 - Setting the Position Controller; Precontrol and Gain

6.4 Setting the position controller
6.4.1 Precontrol and gain
Preconditions and constraints
Before you optimize the position controller, the closed-loop drive speed control must be
optimally set.
Dynamic response and accuracy of the closed-loop position control depend heavily on the lower-
level closed-loop or open-loop control or the motor speed:
• Position control in connection with an optimally set vector control with speed encoder
provides the best results.
• Position control with encoderless vector control (sensorless vector control, SLVC) provides
satisfactory results for most applications. Hoisting/lifting applications require a speed
controller.
• If you operate the position control with the U/f control of drive, then you must take into
account some signi󹪝cant reduction in closed-loop control performance and precision.
Position controllers in hoisting gear
U/f control is not suitable for vertical axes, such as elevating platforms or hoisting gear used in
high-bay racking units, as the axis generally cannot reach the target position as a result of the
limited precision of the U/f control.
Description
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Figure 6-3 Position controller with precontrol
If the speed control of the converter has an encoder to feedback the actual speed, then
deactivate the integral component T
N
of the position controller.
If you use the position control together with the encoderless vector control (SLVC, SensorLess
Vector Control), the positioning accuracy may be inadequate. With active integral time,
positioning accuracy improves.
Commissioning
6.4 Setting the position controller
Basic positioner
Function Manual, 09/2020, FW V4.7 SP13, A5E34257659B AG 47