Adaptive super-twisting sliding mode control for enhanced oxygen excess ratio and temperature regulation in PEM fuel cells for electric vehicles

Abstract In this work, a Super-Twisting Sliding Mode Controller (STSMC) with adaptive gain is designed to manage Oxygen Excess Ratio (OER) and stack temperature in Proton Exchange Membrane (PEM) Fuel Cells (FCs) powering Electric Vehicles (EVs). STSMC contains very advanced types of advanced control systems that provide greater disturbance resilient and stability when operated in conditions that are expected from the system being controlled. Its primary benefit is the use of adaptive gain values; adaptive gain values are obtained using Lyapunov-based stability criteria to improve the system response, reduce response fluctuations compared with standard fixed-gain control strategies, and, in addition to providing a reference for adaptive gain adjustment, provide data that can aid in the development of other types of controllers. Extensive simulation testing has been conducted to verify that this control strategy reduces the time to settle from the active control of a stack to 2.5 s and to exceed the performance of traditional PID controllers (which operate with inertia) in providing improved response to transients. The STSMC resulted in a stack temperature error RMSE of 5 °C (compared with 19.5 °C for the PID controller). The controller further maintains OER within the optimal range and performs effectively during rapid vehicle speed variations. Large-scale comparisons confirm reduced OER tracking indices, with RMSE decreasing from 1.51 to 0.984 and ITAE decreasing from 6.19 to 0.656, reinforcing improved transient behavior. Consequently, the controller enhances energy efficiency and extends Fuel Cell System (FCS) operation in EVs. These findings position STSMC as a significant step toward advanced FC control strategies suited to dynamic EV conditions.