Quick reaching law based global terminal sliding mode control for wind/hydrogen/battery DC microgrid

Abstract

Direct current (DC) microgrids are providing a pathway towards zero-carbon based future. This paper proposes a quick reaching law based global terminal sliding mode control (QRL-GTSMC) for a DC microgrid with hybrid power generation including wind, hydrogen and battery. The proposed control scheme reduces the chattering phenomenon and provides fast reaching time. Furthermore, this study discusses two-level control with system level energy management and device level QRL-GTSMC control. The proposed configuration of DC microgrid includes a complete cycle of hydrogen generation, storage and utilization, which increases the system's complexity but improves flexibility. Firstly, the mathematical models of the wind energy system (WES), fuel cell (FC), electrolyzer, hydrogen tank and battery are developed to study their dynamical behavior. Then, the energy management strategy (EMS) and QRL-GTSMC based low-level controllers are designed. The stability of the control scheme is analyzed through Lyapunov stability criteria. After that, the effectiveness of the proposed framework is demonstrated via MATLAB simulations and compared with conventional PID and terminal sliding mode control. Finally, real-time controller hardware-in-the-loop tests based on TMS320F28379D 32-bit microcontrollers are performed. The simulation and experimental results indicate the stable performance of the DC microgrid under varying weather conditions and system uncertainties while ensuring the asymptotical stability of the whole closed-loop system.