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Group 40: PID Control
The PID Control Macro allows the ACS 140 to take a reference signal
(setpoint) and an actual signal (feedback), and automatically adjust the speed
of the drive to match the actual signal to the reference. Figure 20 on page 60
(APPENDIX) shows the connections of internal signals when the PID Control
macro is selected.
Code Description
4001 PID GAIN
This parameter defines the gain of the PID Controller. The setting range is
0.1... 100. If you select 1, a 10 % change in error value causes the PID
Controller output to change by 10 %.
Table 7
Effect of gain when
PID Gain
0.5
1.0
3.0
* Limited by parameter 2008
4002 PID INTEG TIME
PID controller integration time. Defined as the time in which the maximum output
is achieved if a constant error value exists and the gain is 1. Integration time 1 s
denotes that a 100 % change is achieved in 1 s.
Gain
Gain
4003 PID DERIV TIME
PID controller derivation time. If the process error value changes linearly, D part
adds a constant value into the PID controller output. The derivative is filtered
with a 1-pole filter. The time constant of the filter is defined by parameter 4004
PID DERIV FILTER
100 %
4004 PID DERIV FILTER
Time constant for the filter of D part. By increasing the filter time constant it is
possible to smooth the effect of the D part and suppress noise.
MAXIMUM FREQ
Frequency Change for
a 10 % Change in Error
MAXIMUM FREQ
PID Integration Time
.
Gain
PID derivation time
is 50 Hz.
a 50 % Change in Error
2.5 Hz
5 Hz
15 Hz
.
Control deviation
PID Controller Output
Process Error Value
Frequency Change for
12.5 Hz
25 Hz
50 Hz *
t
t
51
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