The Passive Battery-Supercapacitor Hybrid Energy Storage System’s Current Sharing in Electric Vehicles During Real-life Driving Conditions

Abstract

The main energy source in new electric vehicles (EVs) is batteries, which make up 30-40% of the vehicle’s cost. Because of this situation, the battery requires more care. The battery in battery-powered EVs must either supply large instantaneous loads or obtain energy from regenerative braking, which can shorten the battery’s life and cause deterioration. To increase battery performance and extend battery life, other energy storage systems (ESS) with a high power density are used. Battery performance can be improved by using a supercapacitor (SC), which saves energy from regenerative braking and gives instantaneous power while the battery only supplies average power to EVs. Combining these two energy sources improves system performance and extends battery life. This study demonstrates a passive Hybrid Energy Storage System (HESS) employing a lead acid battery and a supercapacitor under real-world driving situations through Matlab Simulink simulation tests. A comprehensive comparison of current sharing between battery-only ESS and passive HESS has been carried out in order to examine the advantages of passive HESS. The simulation results demonstrate that adding SC at 0.6% of the battery capacity in the passive HESS can lower the maximum battery current by 19.77% when compared to the battery-only system under the same real-life driving conditions.