ABB ACSM1 Firmware Manual page 132

132
26.05 SPEED STEP
Defines an additional speed step given to the input of the speed controller (added to the speed error
value).
-30000...30000 rpm
26.06 SPD ERR FTIME
Defines the time constant of the speed error low pass filter.
If the used speed reference changes rapidly (servo application), the possible interferences in the
speed measurement can be filtered with the speed error filter. Reducing the ripple with 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.
See also parameter
0...1000 ms
26.07 SPEED WINDOW
Defines the absolute value for the motor speed window supervision, ie, the absolute value for the
difference between the actual speed and the unramped speed reference
SPEEDREF RAMP
2.13
is 0.
0...30000 rpm
26.08 ACC COMP DERTIME
Defines the derivation time for acceleration (deceleration) compensation. Used to improve the speed
control dynamic reference change.
In order to compensate inertia during acceleration, a derivative of the speed reference is added to the
output of the speed controller. The principle of a derivative action is described for parameter
DERIVATION
Note: The parameter value should be proportional to the total inertia of the load and motor,
ie, approximately 50...100% of the mechanical time constant (t
constant equation in parameter
If parameter value is set to zero, the function is deactivated.
The figure below shows the speed responses when a high inertia load is accelerated along a ramp.
No acceleration compensation
%
See also parameter
The source for the acceleration compensation torque can also be selected by parameter
COMPENSATION. See parameter group
Parameters and firmware blocks
22.02 SPEED ACT
IN). When the motor speed is within the limits defined by this parameter, signal
bit 8 (AT_SETPOINT) value is 1. If the motor speed is not within the defined limits, bit 8 value
TIME.
Speed reference
Actual speed
26.09 ACC COMP
FW block: SPEED ERROR
Speed step.
FW block: SPEED ERROR
FTIME.
Time constant for speed error low pass filter. 0 ms = filtering disabled.
FW block: SPEED ERROR
Absolute value for motor speed window supervision.
FW block: SPEED ERROR
22.02 SPEED ACT FTIME.
With acceleration compensation
%
t
FTIME.
28.
(see above)
(see above)
(see above)
(1.01 SPEED ACT
(see above)
). See the mechanical time
mech
t
- 3.03
28.04
28.06 ACC