ABB ACS850 Firmware Manual page 141

No. Name/Value
27.10 PID fbk ftime
0.000 ... 30.000 s
27.12 PID gain
0.00 ... 100.00
27.13 PID integ time
0.00 ... 320.00 s
27.14 PID deriv time
0.00 ... 10.00 s
Description
Defines the time constant for the filter through which the
process feedback is connected to the PID controller.
Filter time constant.
%
Unfiltered signal
100
63
Filtered signal
T
-t/T
O = I × (1 - e
I = filter input (step)
O = filter output
t = time
T = filter time constant
Defines the gain for the process PID controller. See
parameter 27.13 PID integ time.
Gain for PID controller.
Defines the integration time for the process PID controller.
Error/Controller output
G × I
G × I
Ti
I = controller input (error)
O = controller output
G = gain
Ti = integration time
Integration time.
Defines the derivation time of the process PID controller. The
derivative component at the controller output is calculated on
basis of two consecutive error values (E
to the following formula:
PID DERIV TIME × (E
K
T = 12 ms sample time
S
E = Error = Process reference - process actual value.
Derivation time.
t
)
O
I
Time
and E
K-1
- E )/T , in which
K-1 S
Parameters 141
FbEq
1000 = 1 s
100 = 1
100 = 1 s
) according
K
100 = 1 s