Commissioning
8.8 Drive optimization
SINAMICS DCM DC Converter
342
Operating Instructions, 12/2018, A5E34763375A
p50051 = 29
Optimization of the speed control for drives with a mechanical system
capable of oscillation
(duration up to 10 min)
The following parameters are set automatically:
p50225
P gain of the speed controller (Kp)
p50226
Integral time of the speed controller (Tn)
p50228
Speed setpoint, smoothing time constant
p50540
Speed controller acceleration time
The frequency response of the controlled system for frequencies between 1
and 100 Hz is recorded during this optimization run.
For this purpose, the drive is first accelerated to a basic speed (p50565,
factory setting = 20%). A sinusoidal speed setpoint with a low amplitude
(p50566, factory setting = 1%) is then switched in. The frequency of this
additional setpoint is changed in 1 Hz increments from 1 to 100 Hz. For
each frequency, an average is generated over a specific time (p50567,
factory setting = 1 s).
The value set at p50567 essentially defines the duration of this optimization
run. For a setting of 1 s it takes about 3 to 4 min.
The measured frequency response of the controlled system forms the basis
for determining its optimal speed controller setting.
WARNING
Uncontrolled motor movement
For motors with a suspended or drawing load, uncontrolled movement can occur during the
optimization run which can lead to death, serious injury or property damage.
•
The optimization run must not be executed if the motor is connected to a mechanical
load that is able to move it while it is in a torque-free state (e.g. a suspended or drawing
load).
Notes regarding optimization runs
For drives with limited travel distance, the optimization run for field weakening (p50051 = 27)
should be interrupted by entering the SHUTDOWN command at the earliest after the 1st field
weakening measuring point has been plotted or the friction characteristic has been plotted
(p50051 = 28) and at the earliest after determining the measuring point at 10% of the
maximum speed - without fault message F60052 being initiated. Once the optimization run in
question (p50051 = 27 or p50051 = 28) has been restarted, it will resume at a more
advanced point, meaning that it can be completed in several stages even in cases where the
travel distance is limited.
