Investigation on Battery Supercapacitor Hybrid Energy Storage Performance based on Frequency Separation Strategy for Electric Vehicle Drive System

Abstract

Currently, applying hybrid energy storage for electric vehicle is inevitable as there is no single energy storage device can satisfactorily fulfill its operational power demand. High energy density of the battery, combined with the high power density of supercapacitor contributes towards not only a longer travel distance but also a good drive response during transient operation e.g. acceleration or regenerative braking. The frequency separation based energy management is among the strategy available to realize energy division between the two energy storage device. This work focuses to investigate how the strategy affects the state of charge performance of the battery under various condition of driving cycles. The design, configuration and simulation of the electrical drive system is carried out with Matlab/Simulation software. The investigation results indicate that the battery current stress is significantly reduced by using the frequency separation strategy, but it does not significantly help to improve the state of charge performance of the battery over the period of the driving cycle.