Robust High Gain Control for Uncertain Hybrid Powertrain Systems in Fuel Cell Electric Vehicles

This paper investigates the dynamics of a hybrid power system (HPS) and powertrain configurations in a fuel cell electric vehicle (FCEV), emphasizing its nonlinear behavior. The study focuses on a hybrid powertrain setup comprising a fuel cell (FC) as the primary source, complemented by an ultracapacitor (UC) and a battery as auxiliary sources, each subject to uncertainties. The system incorporates DC/DC boost converters linking the FC to the DC-Link, and bi-directional converters connecting the UC and battery to the DC-Link. Dynamic models are developed to capture the nonlinear characteristics of the subsystems. The primary goal is to develop a controller capable of simultaneously managing the DC/DC converters amidst uncertainties. A nonlinear control strategy based on Lyapunov theory is proposed to regulate the DC-link voltage and accurately track currents from the sources. The study ensures closed-loop stability under different operating conditions and uncertainties. Simulation results in MATLAB validate the efficacy of the proposed controllers, justifying the UC and battery's ability to meet load demands and enhance fuel cell performance.