ABB ACS880 Firmware Manual page 319

No. Name / Range /
Selection
24.12 Speed error filter
time
0...10000 ms
24.13 RFE speed filter
On
Off
24.14 Frequency of zero
0.50 ... 500.00 Hz
Description
Defines the time constant of the speed error low-pass
filter.
If the used speed reference changes rapidly, the
possible interferences in the speed measurement can
be filtered with the speed error filter. Reducing the
ripple with this filter may cause speed controller tuning
problems. A long filter time constant and fast
acceleration time contradict one another. A very long
filter time results in unstable control.
Speed error filtering time constant. 0 = filtering
disabled.
Enables/disables resonance frequency filtering. The
filtering is configured by parameters 24.13...24.17.
The speed error value coming to the speed controller
is filtered by a common 2nd order band-elimination
filter to eliminate the amplification of mechanical
resonance frequencies.
Note: Tuning the resonance frequency filter requires a
basic understanding of frequency filters. Incorrect
tuning can amplify mechanical oscillations and damage
the drive hardware. To ensure the stability of the speed
controller, stop the drive or disable the filtering before
changing the parameter settings.
0 = Resonance frequency filtering disabled.
1 = Resonance frequency filtering enabled.
1.
0.
Defines the zero frequency of the resonance frequency
filter.
The value must be set near the resonance frequency,
which is filtered out before the speed controller.
The drawing shows the frequency response.
|H (ω)|
20log
10
20
0
-20
-40
-60
0
50
Zero frequency.
100 150
f (Hz)
Parameters 319
Def / Type
FbEq 16b / 32b
0 ms / real32
1 = 1 ms / 1 = 1 ms
Off / uint16
1
0
45.00 Hz / real32
1 = 1 Hz / 100 = 1 Hz