ABB ACS280, Firmware Manual, Page: 162 / 430

162 Parameters
25.04 Speed derivation time
Defines the derivation time of the speed controller.
Derivative action boosts the controller output if the
error value changes. The longer the derivation time,
the more the speed controller output is boosted
during the change. If the derivation time is set to
zero, the controller works as a PI controller, otherwise
as a PID controller. The derivation makes the control
more responsive for disturbances. For simple
applications (especially those without a pulse
encoder), derivative time is not normally required and
should be left at zero.
The speed error derivative must be filtered with a low
pass filter to eliminate disturbances.
The figure below shows the speed controller output
after an error step when the error remains constant.
0.000 s
0.000…10.000 s Derivation time for speed controller. 1000 = 1 s
25.05 Derivation filter time
Defines the derivation filter time constant. See
parameter
25.04 Speed derivation time
.
8 ms
0…10000 ms Derivation filter time constant. 1 = 1 ms
No. Name/Value Description Default
FbEq 16
Gain = K
p
= 1
T
I
= Integration time > 0
T
D
= Derivation time > 0
T
s
= Sample time period = 250 µs
 e = Error value change between two samples
K
p
× T
D
×
 e
T
s
Controller output
e = Error value
Error value
Time
T
I
K
p
× e
K
p
× e
%