lec13_print

lec13_print - Dynamics of Commercial Controllers Srinivas...

Info iconThis preview shows pages 1–7. Sign up to view the full content.

View Full Document Right Arrow Icon
Dynamics of Commercial Controllers Srinivas Palanki University of South Alabama Srinivas Palanki (USA) Dynamics of Commercial Controllers 1 / 18
Background image of page 1

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

View Full DocumentRight Arrow Icon
Commercial Controllers Controller A controller is an electronic device that helps to: 1 regulate a process at its desired set-point despite disturbances to the process. 2 take the system to a new set-point safely, with desired dynamic characteristics. The vast majority of controllers used in the process industry (over 80%) are P, PI or PID controllers. In this lecture, we develop the dynamic models for these commercial controllers. Srinivas Palanki (USA) Dynamics of Commercial Controllers 2 / 18
Background image of page 2
Commercial Controllers Definitions Set-Point, Ysp Controller Signal from sensor, Y Error, E + - Signal to actuator, U Y sp : Desired set-point Y : Signal from sensor E : Error(input to controller) E = Y sp - Y U : Signal to actuator (output of controller) Controller Types P = Proportional PI = Proportional-Integral PID = Proportional-Integral-Derivative Srinivas Palanki (USA) Dynamics of Commercial Controllers 3 / 18
Background image of page 3

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

View Full DocumentRight Arrow Icon
Commercial Controllers P Controller Set-Point, Ysp Controller Signal from sensor, Y Error, E + - Signal to actuator, U U = k c E (1) The variable k c is called the controller gain and is a tunable parameter, which is set by the user. Srinivas Palanki (USA) Dynamics of Commercial Controllers 4 / 18
Background image of page 4
Commercial Controllers PI Controller Set-Point, Ysp Controller Signal from sensor, Y Error, E + - Signal to actuator, U de I dt = E U = k c E + k c τ I e I (2) The variable τ I is called the integral time constant . The PI controller has two tunable parameters: k c and τ I . Srinivas Palanki (USA) Dynamics of Commercial Controllers 5 / 18
Background image of page 5

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

View Full DocumentRight Arrow Icon
Commercial Controllers PID Controller Set-Point, Ysp Controller Signal from sensor, Y Error, E + - Signal to actuator, U de I dt = E de F dt = - 1 λ e F + 1 λ E U = k c E + k c τ I e I + k c τ D ± - 1 λ e F + 1 λ E ² (3) The variable τ D is called the
Background image of page 6
Image of page 7
This is the end of the preview. Sign up to access the rest of the document.

This note was uploaded on 01/07/2011 for the course CHE 452 taught by Professor Dr.srinivaspalanki during the Spring '10 term at S. Alabama.

Page1 / 18

lec13_print - Dynamics of Commercial Controllers Srinivas...

This preview shows document pages 1 - 7. Sign up to view the full document.

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