Hybrid System of Air-Breathing PEM Fuel Cells/Supercapacitors for Light Electric Vehicles: Modeling and Simulation

Abstract

Recently, light electric vehicles such as pedelecs, electric bicycles, and electric scooters have shown excellent potential for short distances. It is essential to control the power required by the electric motor in response to power demand fluctuations. Hybrid energy sources have some essential features to improve efficiency and dynamics. This paper presents a hybrid system of air-breathing proton exchange membrane (PEM) fuel cells (ABFC) and supercapacitors (SC) for operating electric bicycles. Since the supercapacitors meet some of the load variations, the hybrid system offers the opportunity to optimize the air-breathing PEM fuel cells to achieve better fuel consumption and performance. A hybrid dynamic model of the ABFC-SC system is built by using MATLAB Simulink version 9.3 and Simscape Power Systems toolbox for electric bicycles. A web-based software tool used to examine an electric bicycle is employed to create a realistic driving cycle for electric bicycles. The simulation results of the hybrid ABFC-SC system are compared with the results of the ABFC system. The power requirement of an electric bicycle fluctuates depending on the riding conditions, type of electric motor, and control system. The simulation results show that the hybrid ABFC-SC system provides efficient and sufficient energy for an electric bike.