Non-overshoot time response of third order system using cascade PID-Lead compensator controller

In process control industries, one of the major and serious problems is presence of overshoot in controlled variables. This paper deals with elimination of overshoot In step response by using conventional PID controller with cascade lead compensator. In this cascade technique, lead compensator is used in the inner loop and PID controller connected in the outer loop. The process industry consists of many control loops and most of the control loops consists of PI and PID controller. The PI/PID controller is used in the control loop with third or higher order process. The time response is oscillatory due to gain margin and phase margin. The proposed idea is to use the cascade control principle to control the third order system with cascade PID controller and Lead compensator. The compensator is used to compensate the desired phase margin value of system and the PID controller is to control the system with reduced-order response and to suppressing the overshoot. The validity of the proposed approach is verified through simulation for the level control in three tank interacting system.