ABB +N5600 Firmware Instructions page 271

No. Name/Value
25.04 Speed derivation
time
Δe
K × T ×
p D
T
s
0.000 ... 10.000 s
25.05 Derivation filter time
0...10000 ms
Description
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 an encoder), derivative time is not
normally required and should be left at zero.
The figure below shows the speed controller output after an
error step when the error remains constant. The speed error
derivative must be filtered with a low pass filter to eliminate
external disturbances.
%
K × e
p
K × e
p
Gain = K = 1
p
T = Integration time > 0
I
T = Derivation time > 0
D
T = Sample time period = 500 µs
s
Δe = Error value change between two samples
Derivation time for speed controller.
Defines the derivation filter time constant. See parameter
25.04 Speed derivation
Derivation filter time constant.
Controller output
Error value
Time
T
I
time.
Parameters 271
Def/FbEq16
0.000 s
e = Error value
1000 = 1 s
8 ms
1 = 1 ms