ABB ACQ580 - Page 170

166 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,
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
25.15 Proportional gain
em stop
Defines the proportional gain for the speed controller when an
emergency stop is active. See parameter 25.02 Speed
proportional gain.
10.00
1.00…250.00 Proportional gain upon an emergency stop. 100 = 1
25.53 Torque prop
reference
Displays the output of the proportional (P) part of the speed
controller. See the control chain diagram on page 409.
This parameter is read-only.
-
-30000.0…
30000.0%
P-part output of speed controller. See par.
46.03
25.54 Torque integral
reference
Displays the output of the integral (I) part of the speed
controller. See the control chain diagram on page 409.
This parameter is read-only.
-
-30000.0…
30000.0%
I-part output of speed controller. See par.
46.03
No. Name/Value Description Def/FbEq16
Gain = K
p
= 1
T
I
= Integration time > 0
T
D
= Derivation time > 0
T
s
= Sample time period = 250 µs
Δe = Error value change between two samples
K
p
× T
D
×
Δe
T
s
Controller output
e = Error value
Error value
Time
T
I
K
p
×e
K
p
×e
%