ABB ACS880 Series, Firmware Manual

Page: 87 / 764

1560
1380
690
540
1 2 3 4 22.87 (rpm)
(input of function)
22.01 (rpm)
(output of function)
Parameter 22.52 = 540 rpm 1
Parameter 22.53 = 690 rpm 2
Parameter 22.54 = 1380 rpm 3
Parameter 22.55 = 1560 rpm 4
Settings and diagnostics
Parameters: 22.51 Critical speed function … 22.57 Critical speed 3 high (page 307) .
￭ Speed controller autotune
The speed controller of the drive can be automatically adjusted using the autotune
function. Autotuning is based on an estimation of the mechanical time constant
(inertia) of the motor and machine.
The autotune routine will run the motor through a series of
acceleration/deceleration cycles, the number of which can be adjusted by
parameter
25.40 . Higher values will produce more accurate results, especially if
the difference between initial and maximum speeds is small.
The maximum torque reference used during autotuning will be the initial torque
(ie. torque when the routine is activated) plus
25.38 , unless limited by the maximum
torque limit (parameter group 30 Limits ) or the nominal motor torque (parameter
group 99 Motor data ). The calculated maximum speed during the routine is the
initial speed (ie. speed when the routine is activated) + 25.39 , unless limited by
parameter 30.12 or 99.9 .
The diagram below shows the behavior of speed and torque during the autotune
routine. In this example,
25.40 is set to 2.
Program features 87