Author Description

A detailed model of the polarization curve of a fuel cell stack is presented. The time- evolving polarization curve indicates the performance decay of the fuel cell over its lifetime. The performance decay is based on the decrease of electrochemical surface area (ECSA) which is mainly caused by catalyst (Platinum) dissolution. Different degradation factors affecting ECSA reduction were considered and included as additional costs in the power management strategies besides fuel and electricity consumption. The degradation models have been validated against data from the literature to provide an accurate estimate of the lifetime of the hybrid system. We have shown that adding degradation can dramatically change the behavior of power management strategies and affect the optimal sizing between fuel cell and battery for a known drive cycle. Two different real-time strategies, rule-based and model predictive control (MPC)-based, were compared to show that the rule-based strategy actually outperforms MPC. This work represents a comprehensive framework for incorporating degradation into the power management strategies of fuel cell/battery hybrid vehicles, from degradation models to sizing and real-time implementation. We have obtained valuable insights regarding design and energy management strategies of fuel cell vehicles to help future researchers and bring us one step closer towards commercialization of fuel cell vehicles.