Document Type : Research article

Authors

• Sajed Derakhshani Pour ^{1, 2}
• Reza Eslami ²

¹ Department of Energy, Polytechnic University of Milan, Milan, Italy

² Department of Electrical Engineering, Sahand University of Technology, Tabriz, Iran

Abstract

In the last few years, there has been growing attention to isolated DC microgrids (MGs) with robust voltage control and efficient responding to demand in the face of fluctuating demands and supply amounts. This attention is due to significant voltage mismatches originated from the sudden transitions of the load demand and the active power of the supplies such as photovoltaic (PV) systems. To address these goals, a novel nonlinear robust voltage control strategy with a cascaded design consisting of proportional-integral (PI) and sliding mode control (SMC) techniques is developed in this research for the battery energy storage system (BESS). Additionally, this research considers a fuel cell as another power supply in addition to a solar PV system. For maximum power point tracking (MPPT) of the PV system, a novel backstepping sliding mode control (BSMC) technique is developed as well. The effective functioning of the suggested cascaded control strategy is examined using MATLAB/Simulink. The outcomes of the simulation represent the effectiveness of the proposed approach in robustly regulating the voltage level of the DC link at 50 V with small deviations in tracking, and quick reaction to fluctuations in both demand and supply sides, as well as guaranteeing an evenly-distributed responding to demand fluctuations from the DC MG.

Highlights

• Robust nonlinear voltage control in DC microgrids using novel cascaded PI-SMC algorithm.
• Efficient and evenly-distributed responding to fluctuating demand and supply with BESS.
• Novel BSMC technique for maximum power point tracking (MPPT) in PV systems.
• Ensuring stability, less voltage fluctuations, and rapid response to variations.
• Simplified control approach for effective DC link voltage regulation under various scenarios.

Keywords

• DC microgrid
• Cascaded robust voltage control
• Maximum power point tracking
• Battery energy storage system
• Backstepping sliding mode control
• Renewable energy sources

Main Subjects

• Power Systems