Comparison between different energy management algorithms for an urban electric bus with hybrid energy storage system based on battery and supercapacitors

Electric vehicles are an interesting research field for the automotive industry, especially for fully electrical urban buses. Their particular path-defined frequent and consecutive stops close together encourage the usage of supercapacitors, which have a longer service life than rechargeable batteries, and the battery would only be used as a backup energy source. This means a hybrid energy system where an energy management function splits the power request between the two onboard energy storage systems. Two different real-time control algorithms previously developed are briefly presented and numerically tested by means of virtual simulation in order to compare their different behaviour and evaluate their performance compared to an optimal offline control logic based on the dynamic programming approach.