Natural Gas Hydrogen Reformer Controller Design With Disturbance Rejection

In this paper we present a controller design for a linearized model of a fuel cell hydrogen gas reformer, which produces hydrogen from natural gas. We design two feedback control loops, one of them with an integrator and another one with proportional state feedback. In the third step, a feed-forward controller is designed whose role is to off-set for the impact of the disturbance represented by the fuel cell current. Both the feedback controller and the feedforward controller are obtained through a rigorous dynamic optimization process of a quadratic performance criterion along trajectories of a linear dynamic system. According to the presented simulation results, the proposed controller copes well with the disturbance and reduces its impact within a few seconds from the time when the disturbance occurs, despite large jumps in the fuel cell current (disturbance).