Constraint management in fuel cells: A fast reference governor approach

The air supply system in a fuel cell may be susceptible to saturation during transient driving conditions. The air compressor surge and choke can disrupt the How of air into the cathode and negatively impact fuel cell power generation. Low partial oxygen pressure in the cathode can damage the stack and reduce its life. A load governor, added to the air supply control system, can monitor the transients and prevent constraint violation by modifying the reference current command to the fuel cell stack. In this paper we develop such a load governor using two approaches. The first approach is based on on-line model predictive control and the second approach utilizes a fast reference governor. We discuss the performance and computational requirements of each method. We propose a modification to the fast reference governor design to make it applicable to a nonlinear plant.