ABB DCS 400 Manual Download

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II K 4-32

Overview of Software

4.5.5 Armature current controller

The

Arm Cur Nom (1.01)

Arm Cur Max (3.04)

Torque Lim Pos (3.07)

and

Torque Lim Neg (3.08)

parameters are the ones relevant to the current limi-
tation functions.

Arm Cur Nom (1.01)

scales the

power converter to motor rated current. All other
current-dependent parameters are referenced to this
parameter.

Arm Cur Max (3.04)

limits the current

controller absolutely.

Torque Lim Pos (3.07)

and

Torque Lim Neg

(3.08)

limit the reference value

span.

For the self-optimisation function,

only

the

Arm Cur

Nom (1.01)

is relevant. The current controller is

always optimised to 100 %, since the system will more
usually be running in the machine's operating point
than in overload. If you want to optimise to overload,
then the

Arm Cur Nom (1.01)

must be temporarily set

to overload, then optimized, and subsequently reset
again.

Example of an overload parameterization routine

by means of

fixed

parameter settings:

e.g.
Motor nominal current

= 170 A

Overload

= 150%

Speed reference

= analogue input AI1

Parameters affected

Arm Cur Nom (1.01)

170 A

Arm Cur Max (3.04)

150%

Overload Time (3.05)

= 60 s

(*)

Recovery Time (3.06)

= 900 s (*)

Torque Lim Pos (3.07)

150%

Torque Lim Neg (3.08)

-150%

Cur Contr Mode (3.14)

Speed Contr

resp.

Mac-

ro depend

Overload

fix

Speed Ref Sel (5.01)

AI1

resp.

Macro depend

(*) The particulars given here for Overload Time and
Recovery Time are to be construed as examples only.
The actual figures will depend on the overload with-
stand capabilities of the drive components (motor and
power converter), and must be covered by the plan-
ning work.

Second current limitation

The motor’s

maximum

armature current is limited by

the

Arm Cur Max (3.04)

parameter. This absolute

limitation is

always

active. Under this, a second

current limitation function,

Arm Cur Lim 2 (3.24)

switched on and off by a binary signal, can be activat-
ed in the

Curr Lim 2 Inv (9.17)

parameter. This

means it is possible to switch back and forth digitally
between these two limitation functions. The digital
inputs DI1 to DI4 are available as binary signals. With
serial communication, this limitation function can also
be switched over using Bits 11 to 15 of the

Main

Control Word

If the second current limitation function has been
activated in parameter group

9 - Macro Adaptation

the value of the

Arm Cur Max (3.04)

parameter must

be greater than the value of

Arm Cur Lim 2 (3.24)

. In

addition, the

Torque Lim Pos (3.07)

and

Torque Lim

Neg (3.08)

parameters must to set in accordance with

Arm Cur Max (3.04)

The

Arm Cur Max (3.04)

parameter limits the current

to the maximum permissible armature current. This
limitation function is always active, even when the
second current limitation function has not been pa-
rameterised,

Curr Lim 2 Inv (9.17) = Macro depend

Disable

Arm Cur Lim 2 (3.24)

is greater than the

value of

Arm Cur Max (3.04)

120%

150%

-150%

Arm Cur Max
(3.04)

Arm Cur Lim 2
(3.24)

Curr Lim 2 Inv (9.17)