System design and converter control for super capacitor and battery hybrid energy system of compact electric vehicles

In this paper, two main aspects of battery and super capacitor (SC) hybrid energy storage system (HESS) for a compact electric vehicle prototype are introduced. The aspect of system design for EV prototype is presented in detail. The capacity decision method of battery and super capacitor banks for EV application is introduced. For the aspect of control of hybrid energy system, a novel three-layer control strategy for the EV energy and power management is proposed. In order to share the power flow between SC and battery banks, the output current control of super capacitor banks using on three-level converter topologies is proposed. The converter selection and current control method are also presented. All of the works give guidance for designing our EV prototype and HESS platform, which is powered by hybrid energy system as the platform of our further research.