Siemens SINAMICS S120 - Optimizing the Current and Speed Controller

Servo control
4.11 Optimizing the current and speed controller
Drive functions
Function Manual, 11/2017, 6SL3097-4AB00-0BP5
141
4.11
Optimizing the current and speed controller
Note
Controller tuning may only be performed by skilled personnel with a knowledge of control
engineering.
The following tools are available for tuning the controllers:
● Function generator in STARTER
● Trace in STARTER
● Measuring function in STARTER
● Measuring sockets on the Control Unit
Tuning the current controller
The current controller is initialized when the system is commissioned for the first time and is
adequately tuned for most applications.
Tuning the speed controller
The speed controller is set in accordance with the motor moment of inertia when the motor is
configured for the first time. The calculated proportional gain is set to approximately 30% of
the maximum possible gain in order to minimize vibrations when the controller is mounted on
the mechanical system of the machine for the first time.
The integral time of the speed controller is always preset to 10 ms.
The following tuning measures are necessary in order to achieve the full dynamic response:
● Increase the proportional gain K
p_n
(p1460)
● Change the integral time T
n_n
(p1462)
Automatic controller setting of the speed controller (frequency response analysis) in STARTER
● The automatic speed controller setting has the following features:
– Section identification using FFT analysis
– Automatic setting of filters in the current setpoint arm, e.g. for damping resonance
– Automatic setting of the controller (gain factor K
p
, integral time T
n
)
● The automatic controller settings can be verified with the measuring functions.
The "Automatic Controller Setting" parameter screen is selected with the
icon in the
toolbar of the STARTER commissioning tool: