KING FAHD UNIVERSITY CHEMICAL ENGINEERING COURSE NOTES (Process Control)-Lec29

KING FAHD UNIVERSITY CHEMICAL ENGINEERING COURSE NOTES (Process Control)-Lec29

Info iconThis preview shows pages 1–5. Sign up to view the full content.

View Full Document Right Arrow Icon

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: 1 Chapter 11 Stability of Closed-Loop Control Systems Example 11.4 Consider the feedback control system shown in Fig. 11.8 with the following transfer functions: 1 (11-73) 2 1 c c v G K G s = = + 1 1 (11-74) 5 1 1 p d m G G G s s = = = + + Show that the closed-loop system produces unstable responses if controller gain K c is too large. 2 Chapter 11 Figure 11.23. Effect of controller gains on closed-loop response to a unit step change in set point (example 11.1). 3 Chapter 11 Stability Most industrial processes are stable without feedback control. Thus, they are said to be open-loop stable or self-regulating . An open-loop stable process will return to the original steady state after a transient disturbance (one that is not sustained) occurs. By contrast there are a few processes, such as exothermic chemical reactors, that can be open-loop unstable . Definition of Stability. An unconstrained linear system is said to be stable if the output response is bounded for all bounded inputs. Otherwise it is said to be unstable. 4 Chapter 11...
View Full Document

Page1 / 13

KING FAHD UNIVERSITY CHEMICAL ENGINEERING COURSE NOTES (Process Control)-Lec29

This preview shows document pages 1 - 5. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online