4 pi-3# process pid control – GE Industrial Solutions AF-650 GP General Purpose Drive Programming Guide User Manual

Page 137

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PI-20 Process CL Feedback 1 Resource

Option:

Function:

of the first of these signals. The

second input signal is defined in

PI-22 Process CL Feedback 2 Resource.

[0]

*

No function

[1]

Analog Input 53

[2]

Analog Input 54

[3]

Frequency input 29

[4]

Frequency input 33

[7]

Analog Input X30/11 (OPCGPIO)

[8]

Analog Input X30/12 (OPCGPIO)

PI-22 Process CL Feedback 2 Resource

Option:

Function:

The effective feedback signal is made

up of the sum of up to two different

input signals. Select which frequency

converter input should be treated as

the source of the second of these

signals. The first input signal is

defined in PI-20 Process CL Feedback 1

Resource.

[0]

*

No function

[1]

Analog Input 53

[2]

Analog Input 54

[3]

Frequency input 29

[4]

Frequency input 33

[7]

Analog Input X30/11 (OPCGPIO)

[8]

Analog Input X30/12 (OPCGPIO)

3.21.4 PI-3# Process PID Control

Parameters to configure the Process PID Controls.

PI-30 Process PID Normal/ Inverse Control

Option:

Function:

Normal and inverse control are implemented by

introducing a difference between the reference

signal and the feedback signal.

[0]

*

Normal Sets process control to increase the output

frequency.

[1]

Inverse Sets process control to reduce the output

frequency.

PI-31 Process PID Anti Windup

Option:

Function:

[0]

Off

Continues regulation of an error even when the

output frequency cannot be increased or decreased.

[1]

*

On

Ceases regulation of an error when the output

frequency can no longer be adjusted.

PI-32 Process PID Start Speed

Range:

Function:

0 RPM

*

[0 -

6000

RPM]

Enter the motor speed to be attained as a

start signal for commencement of PID

control. When the power is switched on, the

frequency converter will commence ramping

and then operate under speed open loop

control. Thereafter, when the Process PID

start speed is reached, the frequency

converter will change over to Process PID

control.

PI-33 Process PID Proportional Gain

Range:

Function:

0.01

*

[0 - 10] Enter the PID proportional gain. The proportional

gain multiplies the error between the set point

and the feedback signal.

PI-34 Process PID Integral Time

Range:

Function:

10000 s

*

[0.01 -

10000 s]

Enter the PID integral time. The

integrator provides an increasing gain at

a constant error between the set point

and the feedback signal. The integral

time is the time needed by the

integrator to reach the same gain as the

proportional gain.

PI-35 Process PID Differentiation Time

Range:

Function:

0 s

*

[0 - 10 s] Enter the PID differentiation time. The differen-

tiator does not react to a constant error, but

provides a gain only when the error changes.

The shorter the PID differentiation time, the

stronger the gain from the differentiator.

PI-36 Process PID Diff. Gain Limit

Range:

Function:

5

*

[1 - 50] Enter a limit for the differentiator gain (DG). If there

is no limit, the DG will increase when there are fast

changes. Limit the DG to obtain a pure differen-

tiator gain at slow changes and a constant

differentiator gain where fast changes occur.

PI-38 Process PID Feed Forward Factor

Range:

Function:

0 %

*

[0 -

200 %]

Enter the PID feed forward (FF) factor. The FF

factor sends a constant fraction of the reference

signal to bypass the PID control, so the PID

control only affects the remaining fraction of the

control signal. Any change to this parameter will

thus affect the motor speed. When the FF factor

is activated it provides less overshoot, and high

dynamics when changing the set point.

Parameter Descriptions

AF-650 GP Programming Guide

136

DET-618C

3

3

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