ABB ACS560, Firmware Manual

Page: 231 / 514

Parameters 231
25.03 Speed integration
time Defines the integration time of the speed controller. The
integration time defines the rate at which the controller output
changes when the error value is constant and the
proportional gain of the speed controller is 1. The shorter the
integration time, the faster the continuous error value is
corrected. This time constant must be set to the same order
of magnitude as the time constant (time to respond) of the
actual mechanical system being controlled, otherwise
instability will result.
Setting the integration time to zero disables the I-part of the
controller. This is useful to do when tuning the proportional
gain; adjust the proportional gain first, then return the
integration time.
Anti-windup (the integrator just integrates up to 100%) stops
the integrator if the controller output is limited.
The figure below shows the speed controller output after an
error step when the error remains constant. 2.50
0.00…1000.00 s Integration time for speed controller. 10 = 1
No. Name/Value Description Def/FbEq16
K
p
× e
K
p
× e
%
e = Error value
Time
Gain = K
p
= 1
T
I
= Integration time > 0
T
D
= Derivation time = 0
Controller output
T
I