Sizing of Fuel Cell/Supercapacitor Hybrid System based on Frequency Splitting of required Energy

Abstract

Optimal power source sizing and energy management strategies are crucial in the problem of component sizing for hybrid electric vehicles fuel cell. Ensuring cost-effective sizing while meeting power demand necessitates consideration of these factors as well, thereby ensuring a good driving range, reduced energy-loss and consumption, and minimal degradation of fuel cells and batteries for hybrid power sources. The purpose of this work concerns the sizing and the modelling of a power source utilized in a fuel cell hybrid vehicle, the principal source of energy is a Proton Exchange Membrane Fuel Cell, while an Ultra-Capacitor bank serves as an auxiliary source. The sizing algorithm initiates by computing the power demand, which is determined by the mechanical characteristics of the vehicle. This calculation involves considering the instantaneous speed of the chosen drive cycle and the instantaneous road gradient. Subsequently, the algorithm proceeds to determine the mechanical power needed by the motor. In this article, a frequency splitting approach is employed to determine the power distribution between the SC and the fuel-cell for Worldwide Harmonised Light Vehicles Test Procedure (WLTP) driving cycles. The fuel cell operates effectively at low frequencies, whereas the supercapacitor provides power at high frequencies. The efficiencies of every power transformer, including the motor, gearbox, differential, and DC-DC converters, are considered in our work. The data analysis is conducted using the MATLAB software environment. The obtained results demonstrated that the approach outlined in this research article offers a more efficient sizing and energy management between sources in terms of simplicity and adherence to operational conditions of the fuel cell and supercapacitor.