Proton-exchange membrane (PEM) fuel cell system mathematical modelling

Abstract

This work presents a mathematical modelling of a proton-exchange membrane (PEM) fuel cell system integrated with a resistive variable load. The model was implemented using MATLAB Simulink software based on an H-500xp pinch top PEM fuel cell type, and it is used to calculate the reference fuel cell current at various steady-state conditions. The reference current is the input value for the simulation of the PEM fuel cell performance. The model was validated using a Horizon H500xp model fuel cell stack system, with the following components: a 500 W PEM fuel cell, a 13.5 DC volt battery for the start-up, a super-capacitor bank to supply peak loads and a 48 V DC-DC boost converter. In addition, the generated power is dissipated by a variable resistive load. The results from the model shows a qualitative agreement with test bench results, with similar trends for stack current and voltage in response to load and hydrogen flow rate variation. The discrepancies ranged from 5% to 10%, depending on the load resistance applied. Both model and experiments showed a hydrogen conversion efficiency of 80%.