Energy Management Strategy Based on Frequency-Varying Filter for the Battery Supercapacitor Hybrid System of Electric Vehicles

Hybrid Energy Storage System (HESS), which combines the battery and supercapacitor (SC), is a potential solution for the energy system of Electric Vehicles (EV). In this paper, a battery and SC hybrid system for small-scale EV with Energy Management Strategy (EMS) and power interface design is introduced. The energy management and power sharing strategy based on frequency-varying filter method is proposed, aiming to realize both high energy density output and high power density output from HESS. The design and control aspects of the converter as the interface of SC bank are introduced. The experiment results in reduced scale test validate that the energy management strategy is effective and the converter control satisfies the requirement of HESS in our hybrid EV prototype.