P.217), P.215), P.298) – Rockwell Automation FlexPak 3000 Digital DC Drive Version 4.3 User Manual

Page 61

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Configuring the Speed/Voltage Loop

5-13

5.4

Configuring the Speed Loop Forward Path Lag Block

Lag adjustments compensate for noisy feedback or reference signals. The speed loop
lag block serves as a low pass frequency compensation filter. A positive or negative
step input to the lag block drives the output to increase or decrease its value in the
direction of the input. A lower lag break frequency will exhibit a slower step response
than a higher one.

The lag transfer function is:

, where

ω

lag

=

SPD

LOOP

LAG

FREQ

(P.215).

1

1

s

ω

lag

----------

+

--------------------

SPD

LOOP

LAG

BYPASS

(P.217)

Determines if the
speed loop forward
path lag block will act
upon the speed loop
error signal.

Parameter Range:

ON

OFF

Default Setting:

ON

Parameter Type:

Tunable

OIM Menu Path(s):

Speed/Voltage Loop (

SPD

) - Speed/Voltage Loop

(

SPD

) Tuning

If

ON

, the lag block is bypassed and does not affect the speed loop forward path

signal.

SPD

LOOP

LAG

FREQ

(P.215)

Specifies the lag
break frequency for
the speed loop
forward path lag
block.

If

SPD

LOOP

LAG

BYPASS

is

ON

, this

parameter has no
effect.

Parameter Range:

0.01 to 139.62

RAD

/

S

when

FEEDBACK

SELECT

(P.200) =

ARMATURE

VOLT

SPD

LOOP

SCAN

TIME

(P.019) = 10

MS

0.01 to 279.25

RAD

/

S

when

FEEDBACK

SELECT

(P.200)

ARMATURE

VOLT

SPD

LOOP

SCAN

TIME

(P.019) = 5

MS

Default Setting:

1.00

RAD

/

S

Parameter Type:

Tunable

OIM Menu Path(s):

Speed/Voltage Loop (

SPD

) - Speed/Voltage Loop

(

SPD

) Tuning

SPD

LOOP

LAG

OUTPUT

(P.298)

The value
immediately after the
speed loop forward
path lag block.

Parameter Range:

n/a

Default Setting:

n/a

Parameter Type:

Output

OIM Menu Path(s):

SPD

- Speed/Voltage Loop (

SPD

) Test Points

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