modelTestI_bias

Test of the Integral controller with bias

Extends from Modelica.Icons.Example (Icon for runnable examples).

Information

Description

In this example have been tested the Integral controller.
The process to be controlled has the following transfer function

   Y(s)          (1+15s)
   ----  =  ----------------
   U(s)       (1+10s)(1+2s)

There are three processes:

without controller,
with a I controller,
and a I controller with bias signal

The output signal of the process without control is the red line. Of course the system performs poorly, in particular when an external disturb is applied.
In the closed loop system, the integral controller reach the SP with a null steady state error. The disturbance can be rejected using the bias signal of the controller (pink line).

Discrete time

If the model parameter Ts is >=0 the continuous time controllers are replaced by their discrete time versions.
The effect of various discretisation method can be studied.

Parameters

Type	Name	Default	Description
Sampling time
Real	Ts	0	if Ts>=0 then discrete time controller, otherwise continuous time

Components

Type	Name	Default	Description
Modelica.Blocks.Sources.Step	SPstep
I	R
Modelica.Blocks.Math.Feedback	sub2
I	R_Bias
Modelica.Blocks.Math.Feedback	sub3
Modelica.Blocks.Sources.Step	Disturbance
LinearSystems.Continuous.TransferFunction	ProcessCtrl
LinearSystems.Continuous.TransferFunction	processNoCtrl
LinearSystems.Continuous.TransferFunction	ProcessBias
Modelica.Blocks.Math.Feedback	sub1

Revisions

Industrial Control Systems (v 1.0.0) : April-May 2012