ABB ACS180 - Page 77

Program features 77
At zero speed, the 40.05 Process PID trim output act value depends on both the
40.55 Set 1 trim adjust and 40.54 Set 1 trim mix parameter values. However,
adjusting 40.54 Set 1 trim mix near to zero speed will give quick correction.
Example:
If,
parameter 40.52 Set 1 trim selection = Speed
parameter 40.56 Set 1 trim source = PID output
parameter 30.12 Maximum speed = 1500 rpm
parameter 40.53 Set 1 trimmed ref pointer = AI1 scaled
parameter 22.11 Ext1 speed ref1 = AI1 scaled
parameter 12.20 AI1 scaled at AI1 max = 1500
parameter 12.12 AI1 scaled value = 750 (AI1 actual scaled value)
parameter 40.01 Process PID output actual = 100 (limited to 100)
parameter 40.54 Set 1 trim mix = 0.1
parameter 40.55 Set 1 trim adjust = 0.5
then
Combined
The combined mode is suitable for applications where the user needs to maintain
tension from zero speed to maximum speed. The combined mode is a combination of
direct and proportional modes. Here, the trim for zero speed is defined by parameter
40.54 Set 1 trim mix and the trim for speed greater than zero speed is defined by
parameter 40.55 Set 1 trim adjust. The trim value is directly proportional to the value
of parameter 40.53 Set 1 trimmed ref pointer.
The process speed reference is connected in parameter 40.53 Set 1 trimmed ref
pointer
. For example, if EXT1 control mode is used and the reference source is AI1
scaled, then 22.11 Ext1 speed ref1 and 40.53 Set 1 trimmed ref pointer shall be
configured to AI1 scaled.
The 40.05 Process PID trim output act is calculated using the following formula:
Par40.05
100
100
----------


750 0.5=
Par40.05 375=
ACS180 FW.book Page 77 Tuesday, March 9, 2021 2:25 PM