Rockwell Automation FlexPak 3000 Digital DC Drive Version 4.3 - Manual (Page 59)

Configuring the Speed/Voltage Loop 5-11
5.2.4 Configuring Speed Loop Feedback Lead/Lag Block
Lead/lag adjustments compensate for backlash or coupling issues because of the
feedback device.
To enable this block, set SPD LEADLAG SELECT (P.216) to LEAD / LAG or LAG / LEAD . To
disable this block, set SPD LEADLAG SELECT (P.216) to BYPASS .
When this block is enabled, the selected feedback signal is fed into the lead/lag block.
The
SPD LEADLAG LOW FREQ (P.214) and SPD LEADLAG RATIO (P.213) input values are
used to calculate the high break frequency. SPD LEADLAG LOW FREQ (P.214) specifies
the low break frequency and the SPD LEADLAG RATIO (P.213) is the ratio maintained
between the low break and high break frequencies. The low break frequency and ratio
settings are multiplied to determine the high break frequency. For example, if the low
break frequency is 0.50rad/s and the ratio is 10, high break frequency is 5.00 rad/s.
The transfer functions for lead/lag and lag/lead are:
Lead/Lag: Lag/Lead:
Where:
• ω
low
= SPD LEADLAG LOW FREQ (P.214)
• ω
high
= SPD LEADLAG LOW FREQ (P.214)
*
SPD LEADLAG RATIO (P.213)
1
s
ω
low
---------- +
1
s
ω
high
------------ +
----------------------
1
s
ω
high
------------ +
1
s
ω
low
---------- +
----------------------
SPD LEADLAG LOW FREQ (P.214)
Specifies the low
break frequency of
the speed feedback
lead/lag block. Parameter Range: 0.01 to 69.81 RAD / S when:
•
FEEDBACK SELECT (P.200) = ARMATURE VOLT
•
SPD LOOP SCAN TIME (P.019) = 10 MS
0.01 to 139.62 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
If SPD LEADLAG SELECT is set to:
•
BYPASS : This parameter has no effect.
•
LAG / LEAD : This parameter specifies the lead break frequency.
•
LEAD / LAG : This parameter specifies the lag break frequency.