Design of a Nonlinear Integral Terminal Sliding Mode Controller for a PEM Fuel Cell Based on a DC-DC Boost Converter

Abstract

This paper proposes a robust nonlinear controller for a proton exchange membrane fuel cell coupled with a DC-DC boost converter. The key feature is to maintain the desired reference output voltage despite significant disturbances while improving transient stability. In order to do this, a nonlinear robust integral terminal sliding mode controller (ITSMC) is proposed, along with the derivation of the control law, explanation of the reachability analysis, and stability condition. An adapted integral sliding surface is used to capture the dynamics caused by variations in the input voltage and loads. In addition, a modified reaching law is proposed to guarantee the finite time convergence while reducing the chattering. Afterward, the Lyapunov control theory is employed to evaluate the DC-DC boost converter’s large-signal stability while guaranteeing the resilience of the proposed controller. Finally, the applicability of the proposed controller is evaluated through comprehensive analyses on both the simulation platform and the real-time processor-in-loop (PIL) platform under various operating conditions, such as the variation in load resistance, reference output voltage, etc. All of the results, when compared to an existing integral terminal sliding mode controller, indicate quick reference tracking capability with reduced overshoots and robustness against disturbances.