Effect of dead time approximation on controller performance designed for a second order delayed model

The process models for many industrial processes can be represented by a Second Order Plus Dead Time system. In the present analysis, the selected Second Order plus Dead Time model is converted in to First Order plus Dead Time model using Taylor's Series and Skogestad dead time approximation techniques. Controllers have been designed using Internal Model Control method, with various values of desirable closed loop time constants. A comparative study has been performed for closed loop responses for the original and the dead time approximated systems.