How can I best represent an SOPTD in Simulink?

Hi all,

I am trying to express a SOPTD (Second Order Plant with Time Delay) in Simulink to learn about control systems.

What is the best way to do create a SOPTD system?

Can I use a simple (transfer function block + transport delay + gain) ? If so, does the order in which I connect them matter?

Or is there a better way to represent a SOPTD?

Looking forward to your advise.

Thank you!

Answer 1

[Ranjeet]

Hi Bhindhiya,

To represent a second order system with time delay in Simulink, a transfer function block with transport delay can be used. The gain of the plant can be included in the numerator of the transfer function block.

Find the Simulink model attached that simulates a second order plant with time delay and PID controller block to analyse step response. The effect of time delay on transient and steady-state response is also demonstrated.

You may find the article “PID Controller Tuning in Simulink” useful to study the control of second order system.

The Simulink model provided as attachment simulates a second order plant with and without delay. Also control of the system’s response using PID controller has been included. You may use the model as a starting point to experiment with second order system and its control.