ABB ACS180 - Page 78

78 Program features
The following graph shows the trim increase in combined mode.
Note: In the above graph, it is assumed that the PID output is limited or stable at 100.
This is for clarity only. In real life scenarios, PID output can vary based on the setpoint
and actual.
At zero speed, the 40.05 Process PID trim output act value depends on both
parameters 40.54 Set 1 trim mixand 40.55 Set 1 trim adjust. However, adjusting
40.54 Set 1 trim mixnear 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 = 1
Then:
If 12.12 AI1 scaled value is 0:
Par40.05 = (100/100) x {(1500 × 0.1) + [(1 – 0.1) × 0]} × 1
Par40.05 = 150
If 12.12 AI1 scaled value is 750:
Par40.05 = (100/100) x {(1500 × 0.1) + [(1 – 0.1) × 750]} × 1
Par40.05 = 825
40.55 Set 1 trim adjust
40.53 Set 1 trimmed ref pointer
0
40.05 Process PID trim output act
40.54 Set 1 trim mix
Par 40.55
Par 40.54
ACS180 FW.book Page 78 Tuesday, March 9, 2021 2:25 PM