ABB ACS880 Firmware Manual page 264

264 Parameters
No. Name/Value
24.11 Speed correction
-10000.00 ...
10000.00 rpm
24.12 Speed error filter
time
0...10000 ms
24.13 RFE speed filter
Off
On
Description
Defines a speed reference correction, i.e. a value added to
the existing reference between ramping and limitation. This
is useful to trim the speed if necessary, for example to adjust
draw between sections of a paper machine.
Note: For safety reasons, the correction is not applied when
an emergency stop is active.
WARNING! If the speed reference correction
exceeds 21.06 Zero speed
impossible. Make sure the correction is reduced or
removed when a ramp stop is required.
See the control chain diagram on page 648.
Speed reference correction.
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.
0.
1.
limit, a ramp stop may be
Def/FbEq16
0.00 rpm
See par.
46.01
0 ms
1 = 1 ms
Off
0
1