Exhaust Gas Recirculation Control for Large Diesel Engines - Achievable Performance with SISO Design

Abstract

This paper investigates control possibilities for Exhaust Gas Recirculation (EGR) on large diesel engines. The goal is to reduce the amount of $NO_x$ in the exhaust gas by reducing the oxygen concentration available for combustion. Control limitations imposed by the system are assessed using linear analysis of the highly non-linear dynamics. Control architectures are investigated and performance in terms of disturbance rejection and reference tracking are investigated under model uncertainty. Classical feed-forward and feedback controller designs are investigated using classical and Quantitative Feedback Theory (QFT) designs. Validation of the controller is made on the model with focus on disturbance reduction ability.