Robust Tracking Control Design of Hybrid Battery-Supercapacitor Energy Storage System in Electric Vehicles

This article investigates the problem of robust tracking control for a fully active hybrid energy storage system (HESS) in electric vehicles (EVs) consisting of battery and supercapacitor (SC) modules. A modified low-pass filter (MLPF)-based power split strategy is employed to divide the total power demand and generate the reference current for the battery while considering its power limit and the SC’s state of charge (SoC). The SC handles the remaining power and compensates for unknown power losses caused by uncertainties such as modeling inaccuracy and perturbation of model parameters. Additionally, a multiple input-multiple output (MIMO) model-based robust controller design method is proposed to achieve the objectives of accurately tracking time-varying reference current, tightly maintaining the dc bus voltage constant, and automatically compensating for the power deficiency under the disturbance of the ever-changing load. To validate the effectiveness and practical feasibility of the presented control scheme, a formal analysis and simulations of control performances under multiple working scenarios and urban dynamometer driving schedule (UDDS) are conducted. The results demonstrate that the suggested controller exhibits satisfactory static and dynamic performances, possesses strong robustness, and successively achieves all the desired control objectives when combined with the developed power-split strategy.