Feedback Controller Design by Root Locus Technique for Autothermal Reformer System

In this paper, a feedback control design is performed for an autothermal reformer (ATR) based fuel process system for an on-board fuel cell application. The control parameters were designed to regulate the ATR reaction temperature by manipulating air flow rate by using a classical root locus principle. This feedback control design using root locus method was also compared with an internal model control (IMC) method for two strategies of controller design both with and without the feed temperature control to locate the appropriate controller system when the ambient temperature is a major disturbance for cold weather. The simulation results showed that the root locus technique provides better performance than the IMC control technique as given faster rise time than that one. In addition, both control techniques can maintain the response of control variable within the required conditions. As two loops of control system were analyzed, the ATR process combined with the feed temperature control loop can compensate the ambient temperature better than without the feed control loop. It can be concluded that the feedback control strategy using root locus technique can reach desired performance for sustain the adiabatic ATR temperature and give the faster response to control the ATR temperature than IMC method.