Danfoss AKD 5001 Manual page 93

440 Process PID proportional gain
(PROC. PROP. GAIN)
Value:
0.00 - 10.00
Function:
The proportional gain indicates the number of
times the error between the set point and the
feedback signal is to be applied.
Used together with Process control, closed
loop (parameter 100).
Description of choice:
Quick control is obtained by a high gain, but if the gain
is too high, the process may become unstable.
441 Process PID integral time
(PROC. INTEGR. T.)
Value:
0.01 - 9999.99 sec. (OFF)
Function:
The integrator provides an increasing gain at a constant
error between the set point and the feedback signal.
The greater the error, the quicker the gain will increase.
The integral time is the time needed by the integrator
to reach the same gain as the proportional gain.
The gain is proportional to the speed at which
the error changes.
Used together with Process control, closed
loop (parameter 100).
Description of choice:
Quick control is obtained at a short integral time.
However, this time may become too short, which
can make the process unstable.
If the integral time is long, major deviations from
the required set point may occur, since the
process regulator will take a long time to regulate
in relation to a given error.
444 Process PID lowpass filter time
(PROC FILTER TIME)
Value:
0.01 - 10.00
Function:
Oscillations on the feedback signal are dampened
by the lowpass filter in order to reduce their impact
on the process control. This can be an advantage
e.g. if there is a lot of noise on the signal.
= factory setting. () = display text [] = value for use in communication via serial communication port
92
AKD 5000
Used together with Process control, closed
loop (parameter 100).
Description of choice:
0.01
Select the desired time constant (τ). If a time constant
(τ) of 100 ms is programmed, the break frequency
for the lowpass filter will be 1/0.1 = 10 RAD/sec.,
corresponding to (10/2 x π) = 1.6 Hz.
The process regulator will thus only regulate a feedback
signal that varies by a frequency lower than 1.6 Hz. If
the feedback signal varies by a higher frequency than
1.6 Hz, the Process regulator will not react.
OFF
0.01
MG.50.R3.02 -