ABB ACS880-x04, Firmware Manual

Page: 227 / 604

Parameters 227
24.11 Speed correction Defines a speed reference correction, ie. 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 limit , a ramp stop may be
impossible. Make sure the correction is reduced or
removed when a ramp stop is required.
See the control chain diagram on page
587 .
0.00 rpm
-10000.00 …
10000.00 rpm Speed reference correction. See par.
46.01
24.12 Speed error filter
time 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. 0 ms
0…10000 ms Speed error filtering time constant. 0 = filtering disabled. 1 = 1 ms
24.13 RFE speed filter 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.
Off
Off 0. 0
On 1. 1
No. Name/Value Description Def / FbEq16