Motor Control; Constant Speeds; Critical Speeds; Speed Controller Tuning - ABB ACS850 Manual

Motor control

Constant speeds

It is possible to predefine up to 7 constant speeds. Constant speeds can be activated,
for example, through digital inputs. Constant speeds override the speed reference.
Settings
Parameter group 26 Constant speeds

Critical speeds

A Critical speeds function is available for applications where it is necessary to avoid
certain motor speeds or speed ranges because of, for example, mechanical
resonance problems.
Settings
Parameter group 25 Critical speed

Speed controller tuning

The speed controller of the drive can be automatically adjusted using the autotune
function (parameter
of the motor and the machine. It is, however, also possible to manually adjust the
controller gain, integration time and derivation time.
Autotuning can be performed in four different ways depending on the setting of
parameter 23.20 PI tune
the drive torque reference should react to a speed reference step after tuning. The
selection Smooth will produce a slow response;
The selection User
parameters 23.21 Tune bandwidth
information is provided by parameter
fails, the SPEED CTRL TUNE FAIL alarm will occur for approximately 15 seconds. If
a stop command is given to the drive during the autotuning, the routine is aborted.
(page 185).
23.20 PI tune mode). Autotuning is based on the load and inertia
mode. The selections Smooth,
allows customized control sensitivity adjustment through
and
06.03 Speed ctrl
(page 186).
Middle
Tight will produce a fast response.
23.22 Tune damping. Detailed tuning status
stat. If the autotuning routine
Program features 61
and Tight define how