Traction-Braking of an EV in Mountainous Terrain with Hybrid Energy Storage System

This paper discusses the advantages of upgrading the existing battery electric vehicle (BEV) with the proposed configuration of a hybrid energy storage system (HESS). A simple and low-cost configuration for a HESS in an electric vehicle (EV) is analyzed and presented for hilly-driving regions. The performance of the energy storage system (ESS) during hilly terrain traction/braking is enhanced by leveraging the electrical property of each source i.e. Li-ion battery and ultracapacitor (UC). The simulation results show that the UC acts as a source/sink for all the transients during acceleration/deceleration conditions in the hilly driving pattern. Further, the experimental results in this paper show the high electrical stress on the battery that needs to be taken care of during the vehicle traction/electrical braking. Also, there is higher energy recovery when UC is used along with a Li-ion battery in the simplified configuration.