Rockwell Automation 20P PowerFlex Digital DC Drive User Manual

Page 152

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152

Rockwell Automation Publication 20P-UM001I-EN-P - February 2013

Chapter 3

Programming and Parameters

APPL

IC

AT

IONS

PD

Co

nt

ro

l

768

[PD Prop Gain 1]

First proportional gain of the block PD. The value specified in this field depends on
the enabling and configuration of Par 181 [Adaptive Spd En].

Default:

Min/Max:

10.00

0.00 / 100.00

Real

181

770

[Enable PD]

Enables/disables the PD portion of the PID regulator.
Note: This parameter can be assigned to a digital input.

Default:

Options:

0 =

0 =
1 =

“Disabled”

“Disabled”
“Enabled”

16-bit
Int

788

[PD Prop Gain 2]

Second proportional gain of the block PD. The value specified in this field depends
on the enabling and configuration of Par 181 [Adaptive Spd En].

Default:

Min/Max:

10.0

0.0 / 100.0

Real

181

789

[PD Deriv Gain 2]

Second derivative gain of the PD block. The value specified in this field depends on
the enabling and configuration of Par 181 [Adaptive Spd En].

Default:

Min/Max:

10.0

0.0 / 100.0

Real

181

790

[PD Prop Gain 3]

Third proportional gain of the block PD. The value specified in this field depends on
the enabling and configuration of Par 181 [Adaptive Spd En].

Default:

Min/Max:

10.0

0.0 / 100.0

Real

181

791

[PD Deriv Gain 3]

Third derivative gain of the PD block. The value specified in this field depends on
the enabling and configuration of Par 181 [Adaptive Spd En].

Default:

Min/Max:

1.00

0.00 / 100.00

Real

181

PID

Co

nt

ro

l

418

[Real FF PID]

Represents the feed–forward value which has been recalculated according to the
PI correction. It will be calculated with the following formula:
Par 418 [Real FF PID] = (Par 758 [Feed Fwd PID] / 1000 ) x Par 771 [PI Output]
When either the negative or positive limit of this parameter has been reached,
further increases in the value of Par 771 [PI Output] will be blocked in order to
avoid undesirable saturation of the PID regulator. For example:
When Par 758 [Feed Fwd PID] = +8000, the positive limit of Par 771 [PI Output]
will be automatically set at 10000 / ( 8000 / 1000 ) = 1250.

Default:

Min/Max:

Read Only

–/+10000

16-bit
Int

758,
771

757

[PID Clamp]

The PID “clamp” allows a smooth tension setting of a controlled system winder/
unwinder when the calculation of the initial diameter function cannot be used.
When enabling the drive, the dancer is at the lowest point of its full scale. In this

case, with Par 759 [PID Error] at its maximum value, the motor could accelerate
too fast to properly configure the dancer for its central operating position. By
setting the value of Par 757 [PID Clamp] sufficiently low. e.g, = 1000, when the
drive starts and Par 770 [Enable PD] = 1 “Enable”, the value of Par 759 [PID
Error] is limited to 1000 until the signal coming from the dancer (via Par 763
[PID Feedback]) goes above the value in this field. Then, the value of [PID
Clamp] is automatically returned to its maximum value of 10000. The PID clamp
is kept at 10000 until the drive stops or Par 770 [Enable PD] = 0 “Disabled”.

Default:

Min/Max:

10000

0 / 10000

16-bit
Int

759,
763,
770

758

[Feed Fwd PID]

Feedback from the transducer position (dancer) or tension.

Default:

Min/Max:

Read Only

–/+10000

16-bit
Int

759

[PID Error]

Error value input to the PID function (output of the PID Clamp block).

Default:

Min/Max:

Read Only

–/+10000

16-bit
Int

760

[PID Setpoint 0]

First offset value added to Par 763 [PID Feedback]. This parameter can be assigned
to an analog input, for example, for the tension setting when a load cell must be
used as feedback.

Default:

Min/Max:

0

–/+10000

16-bit
Int

763

761

[PID Setpoint 1]

Second offset value added to Par 763 [PID Feedback].

Default:

Min/Max:

0

–/+10000

16-bit
Int

763

762

[PID Setpoint Sel]

Selects the offset value added to Par 763 [PID Feedback]. This parameter can be
assigned to a digital input.

Default:

Options:

0 =

0 =
1 =

“Setpoint 0”

“Setpoint 0”
“Setpoint 1”

16-bit
Int

763

Fil

e

Gr

oup

No

.

Parameter Name & Description

See

page 110

for symbol descriptions

Values

Da

ta

T

yp

e

Rela

ted

A

A

A

A

A

A

A

A

A

A

A

A

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