Optimal sizing of hybrid supply for electric vehicle using Li-ion battery and supercapacitor

Currently, the automakers use Lithium-ion battery like an energy storage system for vehicle propulsion. However the battery power is limited by two deferent rates of charge and discharge, what can limit the recovered energy during the brake phase. On the other hand, the supercapacitor is a powerful component which can deliver very high power pulse for the both charging and discharging phases. This paper describes a methodology for designing hybrid supply using Li-ion Batteries and supercapacitors for electric vehicle application taking in the account the energetic characteristics and powers limitations of battery and supercapacitor. The method developed in this paper allows us to estimate the optimal level of hybridization and gives us the best technologies to operate this hybridization. An example which illustrates these ideas is proposed and the sizing results of available energy using a hybrid supply are compared with those obtained using the battery like vehicle supply.