Proposed hysteresis energy management strategy based on storage system efficiency for hybrid electric vehicle

Abstract

Varieties of energy management strategies have been developed to control the flow of energy between the traction system and different sources. Many of these control techniques consider as inputs variables the state of charge of the energy storage system (ESS), and the required power by the vehicle to provide the optimal fuel cell power reference. This paper proposes an energy management strategy that gathers the state of charge and the required power using the expression of the ESS converter efficiency as a sole input variable of the energy management. The latter is based on hysteresis control that allows generating the reference power of the fuel cell for each level of the converter efficiency. The topology of the electric vehicle is composed with the proton exchange membrane fuel cell as the main source and ultra-capacitor devices as the auxiliary source. Simulation results show that the proposed strategy allows energy distribution between the sources and the traction system while respecting the constraints on the different systems. Therefore, the energy consumption is reduced by using the fuel cell system and the storage converter on their high efficiencies