Effect of Oxygen Excess Ratio on the Performance of a Hybrid Fuel Cell System

This paper considers the significant impact of the oxygen excess ratio (OER) on the hydrogen consumption of a hybrid fuel cell (FC) system. To do so, firstly, a hybrid FC system, composed of an FC stack and a battery pack, is developed in a simulation environment. Subsequently, sequential quadratic programming (SQP), as an optimization-based energy management strategy (EMS), is utilized to minimize hydrogen consumption while respecting the operating constraints of the power sources. Herein, the primary objective is to evaluate the contribution of the OER to the improvement of the FC performance. In this respect, the EMS is equipped with an optimal OER tracker, and its performance is compared with the case where the OER is constant. The results of this study indicate that following an optimal trajectory of OER reduces the hydrogen consumption by nearly 3% under a standard mission profile at sea level conditions.