ABB ACS560 Firmware Manual page 58

58 Program features
Combined
The combined is suitable for applications where you need to maintain tension from
zero speed to maximum speed
Combined method is a combination of direct and proportional mode. Here, the trim for
zero speed is defined by
speed is defined by
value of 40.53 Set 1 trimmed ref
The process speed reference is connected in
example, if EXT1 control mode is used and the reference source is AI scaled, then
22.11 Ext1 speed ref1
AI1 scaled.
The 40.05 Process PID trim output act
 
Par40.05 = Par30.12
The below graph shows the trim increase in combined mode.
40.55 Set 1 trim adjust
Note: In the above graph, it is assumed that the PID output is limited/stable at 100.
This is for understanding purpose only. In real case scenario, PID output can vary
based on the setpoint and actual.
Example
If,
Par. 40.52 Set 1 trim selection
Par. 40.56 Set 1 trim source
Par. 30.12 Maximum speed
Par. 40.53 Set 1 trimmed ref pointer
Par. 22.11 Ext1 speed ref1
Par. 12.20 AI1 scaled at AI1 max
40.54 Set 1 trim mix
40.55 Set 1 trim adjust. The trim value is directly proportional to
pointer.
and 40.53 Set 1 trimmed ref pointer
 
Par40.54
0
40.53 Set 1 trimmed ref pointer
= Speed
= PID output
= 1500 rpm
= AI1 scaled
= AI1 scaled
= 1500
and the trim for speed greater than zero
40.53 Set 1 trimmed ref
is calculated using below formula:
  
+ 1 Par40.54 –
pointer. For
should be configured to
   
Par40.53 Par40.55
40.55 Set 1 trim adjust