6-45
6
îš‹ Stabilizing Speed (Automatic Frequency Regulator)
The speed feedback detection control (AFR) function controls the stability of the speed when a load is sud-
denly applied or removed. It calculates the amount of speed fluctuation using the torque current (Iq) feedback
value and compensates the output frequency with the amount of fluctuation.
Fig 6.47 AFR Control Loop
îš„Related Parameters
îš„Setting the AFR Gain (n2-01)
Normally there is no need to change this setting. If adjustments are necessary do the following:
If hunting occurs increase n2-01.
If the response is too low, decrease n2-01.
Adjust the setting by 0.05 at a time while checking the response.
îš„Setting the AFR Time Constants 1 and 2 (n2-02, n2-03)
Normally the setting value of n2-02 is used as AFR time constant (T in Fig 6.47). The setting value of n2-03 is
used when:
L2-04 is set to 1 or 2 AND
output frequency >
5 Hz AND
a transient load change occurs (causing transient regeneration or overshoot at acceleration).
If OV faults occur (e.g. at the end of the acceleration) increase n2-02 and especially n2-03.
In order to prevent hunting effects caused by different response behaviours of the AFR and the Torque Com-
pensation function C4-02 should be increased together with n2-02 and n2-03.
Parameter
No.
Name
Factory
Setting
Change
during
Opera-
tion
Control Methods
V/f
V/f with
PG
Open
Loop
Vector
Closed
Loop
Vector
n2-01 Speed feedback detection control (AFR) gain 1.00 No No No A No
n2-02 Speed feedback detection control (AFR) time constant 50 ms No No No A No
n2-03 Speed feedback detection control (AFR) time constant 2 750 ms No No No A No
I
q
f
out
f
ref
To Next Page
Loading...
Need help?
General