Simplified Design of PI Controller Based on CDM

This paper presents the simplified design of a PI controller for a higher-order plant by using the concept of plant model reduction and coefficient diagram method with less number of stability index gamma _i. The higher-order plant model is first reduced to be a lower-order plant model by ignoring its non-dominant poles. Secondly, the PI controller is designed for the lower-order plant model by using coefficient diagram method with the appropriate values of stability index in order to obtain its system response without overshoot. Thirdly, the designed PI controller is used to control the original higher-order plant. The simulation results show that the PI controller designed from the lower-order plant model is sufficient for controlling the original higher-order plant with acceptable performance