Improved Operating Efficiency
6-
23
Stabilizing Speed (Speed Feedback Detection Function)
The speed feedback detection control (AFR) function measures the stability of the speed when a load is sud-
denly applied, by calculating the amount of fluctuation of the torque current feedback value, and compensat-
ing the output frequency with the amount of fluctuation.
Related Constants
Constant
Number
Name
Description
Setting
Range
Factory
Setting
Change
during
Operation
Control
Methods
MEMOBUS
Register
Open-
loop
Vector
Flux
Vector
Display
n2-01
Speed feedback
detection control
(AFR) gain
Set the internal speed feedback
detection control gain using the
multiplication function.
Normally, there is no need to
make this setting.
Adjust this constant as follows:
• If hunting occurs, increase
the set value.
• If response is low, decrease
the set value.
Adjust the setting by 0.05 at a
time, while checking the
response.
0.00 to
10.00
2.00
No
A
No
5D0H
AFR Gain
n2-02
Speed feedback
detection control
(AFR) time constant
Set the time constant to decide
the rate of change in the speed
feedback detection control.
0 to
2000
250 ms
No
A
No
5D1H
AFR Time
n2-03
Speed feedback
detection control
(AFR) time constant 2
Increase the setting if overvolt-
age (OV) failures occur at the
completion of acceleration or
when the load changes radi-
cally.
0 to
2000
750 ms
No
A
No
5D2H
AFR Time 2
n2-0
5
Starting gain for AFR
gain change
Set the gain to the AFR gain in
0 Hz.
The hunting by AFR is con-
trolled at the time of a low
speed (0-12 Hz).
0.00 to
2.00
0.20
No
A
No
5D4H
AFR G of Start
