An Efficient Reference Modulation Based Control Strategy for Active Hybrid Energy Management of EVs

In the hybrid energy storage system of electric vehicles (EVs), supercapacitors (SCs) are configured to supplement high frequency power loads to reduce battery strains. Continuous supply and quick response to power load through bidirectional power control is of great importance to attain power balance and keep the stability of bus voltage. In this paper, we propose a reference modulation based power management strategy to tackle this problem. Specifically, an adaptive SCs reference current regulation is designed to maintain sustainable power supply for SCs. A discrete lead compensator based reference smoothing control technique is integrated in to bottom layer control in order for quick transient response to stochastic power demand. With the designed SCs current regulation and reference smoothing technique, we aim to reduce the fluctuation of bus voltage. US06 driving cycles are applied in simulation and experiment to verify the effectiveness of the proposed approach.