Rockwell Automation FlexPak 3000 Digital DC Drive Version 4.3 - Manual (Page 100)

9-6 FlexPak 3000 DC Drive Software Reference
9.2.2 Configuring the Outer Control Loop Forward Path
The difference between the OCL RAMP OUTPUT (P.846) and OCL feedback signal (after
lead/lag has been applied, if selected) is summed with the OCL feedback and then fed
into a PI block. In the PI block, gain ( OCL PI PROP GAIN (P.808)) and lead frequency ( OCL
PI LEAD FREQ (P.809)) are applied. The output of the PI block is clamped within the
values of OCL PI POSITIVE LIMIT (P.810) and OCL PI NEGATIVE LIMIT (P.811).
The signal from the PI block is fed into the OCL trim range block. Trim determines the
amount of control the OCL signal has on the speed/voltage loop reference. The amount
of trim is set through OCL TRIM RANGE (P.812).
OCL REF REGISTER
(P.801)
The reference for the
outer control loop that
is used when
OCL
REFERENCE SELECT
(P.800) is set to
REGISTER .
Parameter Range: –4095 to 4095
Default Setting: 0
Parameter Type: Tunable
OIM Menu Path(s): Outer Control Loop ( OCL ) - OCL Configure
Typically used in applications where a constant reference is needed.
OCL REF ROUNDING (P.803)
Specifies the amount
of reference
smoothing (rounding)
for the outer control
loop. Parameter Range: 0 to 50%
Default Setting: 0%
Parameter Type: Tunable
OIM Menu Path(s): Outer Control Loop ( OCL ) - OCL Tuning
It is set as a percentage of OCL REF RAMP TIME . Rounding is performed at the
beginning and end of an OCL reference change.
If OCL REF ROUNDING is set to 0%, the OCL performs a linear ramp function. If it is set
to 50%, the entire ramp time is smoothed: 50% at the beginning of the reference
change and 50% at the end. If
OCL REF RAMP TIME (P.802) is 0.0 (S-curve block
bypassed), OCL REF ROUNDING has no effect on the OCL reference signal.
Figure 9.3 – OCL Reference Signal Rounding