Setpoint PI controllers for systems with large normalized dead time

This paper derives proportional-integral (PI) control algorithms for first-order plants with time lag. First, the effects of proportional control on overshoot and rise time are analyzed. Then these results are applied to aid in the design of PI controllers that utilize a pole-zero cancellation. New PI tuning methods are proposed for design criteria typical of those found in metal rolling mill applications with large normalized dead time.