Group 40: Process Pid Set 1 - ABB ACS550-01 User Manual

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Group 40: Process PID Set 1

This group defines a process PID control operation mode for the drive. In PID control
mode, the drive compares a reference signal (setpoint) to an actual signal
(feedback), and automatically adjusts the speed of the drive to match the two
signals. The difference between the two signals is the error value.
Three groups of parameters define PID control:
• Group 40 Process PID Set 1 defines process PID Set 1. Normally, this parameter
set is used.
• Group 41 Process PID Set 2 defines process PID Set 2.
Both Group 40 and 41 have the same parameters, except for the parameter used
to select the PID set (4027).
• Group 42 External / Trimming PID defines:
– an external PID control parameters or
– trimming input parameters for speed /frequency reference.
Code Description
4001 GAIN
Defines the PID Controller's gain.
• The setting range is 0.1... 100.
• At 0.1, the PID Controller output changes one-tenth as much as the error value.
• At 100, the PID Controller output changes one hundred times as much as the error value.
4002 INTEGRATION TIME
Defines the PID Controller's integration time.
Integration time is, by definition, is the time required to increase
the output by the error value:
• Error value is constant and 100%.
• Gain = 1.
• Integration time of 1 second denotes that a 100% change is
achieved in 1 second.
0.0 = – Disables integration (I-part of controller).
NOT SEL
0.1...600.0 = Integration time (seconds).
4003 DERIVATION TIME
Defines the PID Controller's derivation time.
• You can add the derivative of the error to the PID controller
output. The derivative is the error value's rate of change. For
example, if the process error value changes linearly, the
derivative is a constant added to the PID controller output.
• The error-derivative is filtered with a 1-pole filter. The time
constant of the filter is defined by parameter 4004
.
FILTER
0.0 = – Disables the error-derivative part of the PID
NOT SEL
controller output
0.1...10.0 = Derivation time (seconds)
Start-Up
D (P 4001 = 10)
C (P 4001 = 1)
A = Error
B = Error value after stop
C = Controller output with Gain = 1
D = Controller output with Gain = 10
Error
100%
PID DERIV
0%
PID output
Gain
P 401
ACS550 User's Manual
A
B
P 4002
Process Error Value
t
D-part of controller output
P 4003
t
t