Nonlinear control of hybrid energy storage system for hybrid electric vehicles

Rapidly evacuating fossil fuels, oil, natural gas assets, and environmental effects has made the hybrid electric vehicles more effective than conventional vehicles. There are a larger number of researches that have been carried out on fuel cell-based electric vehicles. This paper presents the nonlinear control that deals with hybrid energy storage system (HESS) for hybrid electric vehicles. HESS consists of two sources: a fuel cell and supercapacitor. Fuel cell acts as the main source while supercapacitor as the auxiliary source. These two sources are associated with bus bar link via power electronic circuitry to harness the power from these sources at single platform. A nonlinear control technique with merging effects of sliding mode and backstepping control is applied to attain the following control goals: (a) better DC bus voltage regulation, (b) reference tracking of fuel cell current and supercapacitor current, and (3) global stability of proposed system. The main reason behind applying the sliding mode-based backstepping control is because of nonlinearities present in the nature of the system. The simulation has been performed on Matlab/Simulink to ensure the fast convergence, better DC voltage regulation, and error-free reference tracking with zero initial overshoot to meet all the control objectives.