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230 Parameters
Speed error window
control enable
Enables/disables (or selects a source that 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
operating mode is active (see parameters
and
), or when the drive is a speed-controlled follower (see
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 (
)
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
.
The window boundaries are defined by
as follows:
(rather than
) that 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).
WARNING!
In a speed-controlled follower, the speed
error window must not exceed
for a reliable ramp stop. Make sure both
and
are smaller than
(or speed error window control
disabled) when a ramp stop is required.
0 = Speed error window control disabled
1 = Speed error window control enabled
Disable
0.
0
No.
Name/Value
Description
Def
/
FbEq16
Speed (rpm)
0 rpm
Ref [
] rpm
Reference
Reference - [
] rpm
Ref [
] rpm
Reference
Reference - [
] rpm
Speed error
window
Speed error
window
Forward
Reverse
Summary of Contents for ACS880-x04
Page 1: ... ABB INDUSTRIAL DRIVES ACS880 primary control program Firmware manual ...
Page 4: ......
Page 18: ...18 Using the control panel ...
Page 24: ...24 Control locations and operating modes ...
Page 112: ...112 Application macros ...
Page 496: ...496 Additional parameter data ...
Page 544: ...544 Fault tracing ...
Page 602: ...602 Control chain diagrams ...