LQ-MPC Design for Degradation-Conscious Control of PEM Fuel Cells

Abstract

This paper presents a formulation for degradation-conscious control of polymer electrolyte membrane (PEM) fuel cells with the particular goal of improving the membrane's mechanical durability. Specifically, a 1D through-the-membrane model of the PEM fuel cell is developed as the plant model based on the authors' previous work. The model is two-phase, non-isothermal, and has 36 states in total. This model is then reduced for control purposes to obtain an 8-state, parameter varying model that retains the main features of the full-order model. The reduced model is then linearized about the current operating point to render a linear model for a linear quadratic model predictive control (LQ-MPC) problem formulation. The control objective is to meet a power demand while satisfying various constraints on membrane hydration and temperature, liquid accumulation in the catalyst layers, and actuator limits. Simulation results demonstrate the promise of the resulting LQ-MPC framework in enabling degradation-conscious control for PEM fuel cells.