Improving sustainability in urban and road transportation: dual battery block and fuel cell hybrid power system for electric vehicles

Abstract

This work aims to study and analyze sustainability improvement in urban and road transportation by using a hybrid power system for electric vehicles consisting of a dual low- and high-rate operation lithium battery block and a fuel cell. The proposed power system reduces the energy consumption in electric vehicles, thus helping to enhance a sustainable process of environmental urban pollution and reducing or eliminating fossil fuel dependence, enhancing global sustainability. In this configuration, the high-rate lithium battery powers the electric vehicle in high-power-demand processes like acceleration mode or on an uphill road; the low-rate battery operates at a low output power range, servicing the auxiliary systems and low power loads, and the fuel cell supplies energy in intermediate-power-demand conditions, normal driving mode, constant velocity, or flat and downhill terrain. The dual power system improves global efficiency, since every power unit operates optimally, depending on the driving conditions. Power sharing optimizes the lithium battery performance and fuel cell capacity, minimizing the size and weight of each energy system and enlarging the driving range. A comparative study between different lithium battery configurations and fuel cells shows an efficiency improvement of 31.4% for the hybrid dual-battery block and fuel cell operating in low, high, and intermediate output power ranges, respectively. The study is based on a simulation process recreating current driving conditions for electric cars in urban, peripheral, and intercity routes. An alternative solution consisting of a hybrid system, fuel cell, and high-rate lithium battery produces a 29% power gain.