ABB ACS880 Firmware Manual page 267

No. Name/Value
24.41 Speed error window
control enable
Disable
Enable
Other [bit]
Description
Enables/disables speed error window control, sometimes
also referred to as deadband control or strip break
protection. It forms a speed supervision function for a
torque-controlled drive, preventing the motor from running
away if the material that is being held under tension breaks.
Note: Speed error window control is only effective when the
Add operating mode is active (see parameters
19.14), or when the drive is a speed-controlled follower (see
page 75).
In normal operation, window control keeps the speed
controller input at zero so the drive stays in torque control.
If the motor load is lost, then the motor speed will rise as the
torque controller tries to maintain torque. The speed error
(speed reference - actual speed) will increase until it exits
the speed error window. When this is detected, the
exceeding part of the error value is connected to the speed
controller. The speed controller produces a reference term
relative to the input and gain
gain) which the torque selector adds to the torque reference.
The result is used as the internal torque reference for the
drive.
The activation of speed error window control is indicated by
bit 3 of 06.19 Speed control status
The window boundaries are defined by
window high and 24.44 Speed error window low
Speed error
window
Forward
Reverse
Speed error
window
Note that it is parameter
defines the overspeed limit in both directions of rotation.
This is because the function monitors speed error (which is
negative in case of overspeed, positive in case of
underspeed).
0 = Speed error window control disabled
1 = Speed error window control enabled
0.
1.
Source selection (see Terms and abbreviations
152).
19.12
(25.02 Speed proportional
word.
24.43 Speed error
Speed (rpm)
Reference + [24.44] rpm
Reference
Reference - [24.43] rpm
0 rpm
Reference + [24.43] rpm
Reference
Reference - [24.44] rpm
24.44 (rather than 24.43) that
on page
Parameters 267
Def/FbEq16
Disable
and
as follows:
0
1
-