Parameter Group 3 - Pid Control - Emerson PACMotion VFD Series User Manual

Parameter Group 3 – PID Control
Overview
PACMotion VFD provides an internal PID controller. Parameters for configuration of the PID controller are
located together in Group 3. For simple applications, the user needs to only define the setpoint source (P3-05
to select the source or P3-06 for a fixed setpoint), feedback source (P3-10) and adjust the P Gain (P3-01),
I time (P3-02) and optionally the differential time (P3-03).
The PID operation is uni-directional, and all signals are treated as 0 – 100% to provide a simple, intuitive
operating format.
Table 37: Parameter Group 3 – PID Control
Par Parameter Name
P3-01 PID proportional gain
PID Controller Proportional Gain. Higher values provide a greater change in the drive output frequency in
response to small changes in the feedback signal. Too high a value can cause instability.
P3-02 PID integral time
PID Controller Integral Time. Larger values provide a more damped response for systems where the overall
process responds slowly.
P3-03 PID differential time
PID Differential Time Constant.
P3-04 PID operating mode
0 Direct
1 Inverse
P3-05 PID reference select
0 Digital preset
1 Analog Input 1
2 Analog Input 2
P3-06 PID digital reference
When P3-05 = 0, this parameter sets the preset digital reference (setpoint) used for the PID Controller.
Where the feedback is provided from a transducer such as a pressure transducer or level measurement,
this represents the percentage of the pressure range (e.g. for a 0 – 10 Bar transducer, 4 bar = 40%) or the
level.
P3-07 PID output upper limit
Limits the maximum value output from the PID controller.
P3-08 PID output lower limit
Limits the minimum output from the PID controller.
P3-09 PID output limit select
0 Digital Output Limits
1 Upper limit set by analog
input 1
2 Lower limit set by analog
input 1
3 PID output added to analog
input 1
P3-10 PID feedback select
0 Analog Input 2
1 Analog Input 1
2 Motor Current
3 DC Bus Voltage
4 Differential : Analog Input 1 – Analog Input 2
5 Largest Value : Analog Input 1 or Analog Input 2
GFK-3111A
Use this mode if an increase in the motor speed should result in an
increase in the feedback signal.
Use this mode if an increase in the motor speed should result in a
decrease in the feedback signal.
P3-06 is used.
Analog Input 1 as displayed in P0-01 is used.
Analog Input 2 as displayed in P0-02 is used.
The output range of the PID controller is limited by the values of P3-07
& P3-08.
The output range of the PID controller is limited by the values of P3-08
& the signal applied to Analog Input 1.
The output range of the PID controller is limited by the signal applied to
Analog Input 1 & the value of P3-07.
The output value from the PID Controller is added to the speed
reference applied to the Analog Input 1.
PACMotion VFD AC Variable Speed Drive User Guide
Minimum Maximum Default
0.0 30.0
0.0 30.0
0.00 1.00
0 1
0 2
0.0 100.0
P3-08 100.0
0.0 P3-07
0 3
0 5
Units
1.0 -
1.0 s
0.00 s
0 -
0 -
0.0 %
100.0 %
0.0 %
0 -
0 -
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