“…Fang, 2015 [8], for example, modeled a hydrogen injection subsystem, consisting of gaseous fuel injectors that offer greater flexibility for controlling the anode pressure, and consequently for compensating abrupt pressure reduction when purge occurs. But a major concern in the system management is the air supply subsystem; herein the problems of oxygen excess ratio regulation, equalization of anode and cathode pressures and water management control are essentially addressed in PEMFC control studies using a variety of techniques, e.g., nonlinear model-based predictive control of gas pressures was applied to deal with different events of errors in PEMFC systems, along with several types of dynamic load changes [9,10]. It has been acknowledged that oxygen excess ratio control is one of the most important actions to enhance protection and performance of fuel cells; thus, well-suited control strategies with this target have been proved, three related works are the following: a sliding mode control achieved by adjusting the compressor supply voltage was assisted with a nonlinear observer predicting the oxygen excess ratio and improved with a novel tuning procedure [11].…”