24-11-2010, 05:00 PM
[attachment=7270]
Basic Process Control
pen vs Closed Loop
! Closed loop
! Automatic control
! Open Loop
! Manual control
! Person takes the place of the controller
A problem
Output initially 50%, Gain = 2, reset = 2 minutes per repeat
A direct acting controller control is subjected to a sustained
error of 5%
What is the output after 4 minutes?
Proportional Response = ke = 2x5=10%
Integral Action- in 4 minutes the control will go through 2 repeats.
Integral action = 2 x 10 = 20%
Total output change is proportional + integral = 30%