ABB ACQ80, Firmware Manual

Page: 133 / 390

Parameters 133
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.
Note: ABB recommends not to change the
default value. This can impact the MPPT
efficiency.
0.50
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