An Efficient Control Strategy for Battery – Supercapacitor Hybrid Energy Storage in a PV-Based DC Microgrid

Abstract

The proliferation of microgrid architectures, particularly direct current (DC) microgrids, has accelerated in response to the increasing penetration of renewable energy resources integrated with advanced energy storage systems. Such configurations offer notable technical advantages, including the mitigation of harmonic distortion and improved system stability. However, the inherent intermittency and stochastic behavior of renewable generation sources, such as photovoltaic (PV) arrays and wind turbines, necessitate the incorporation of energy storage solutions to enhance system reliability, operational resilience, and overall performance. In this context, the present study develops and simulates an isolated DC microgrid framework comprising a photovoltaic generation unit, a hybrid energy storage system integrating batteries and supercapacitors, interfacing power electronic converters, and a constant load profile. A proportional–integral (PI)-based energy management strategy is implemented to regulate power flow, ensure efficient energy distribution, and sustain stable islanded operation. The control architecture further incorporates maximum power point tracking (MPPT) for optimal PV energy extraction, state-of-charge (SOC) regulation for storage coordination, and advanced converter control mechanisms to preserve DC bus voltage stability. Additionally, a relay-based protection scheme is deployed to mitigate the risk of excessive battery depth-of-discharge. The system model is developed within the MATLAB/Simulink environment, enabling comprehensive dynamic analysis under varying operating conditions. Simulation results substantiate the capability of the proposed microgrid configuration to reliably satisfy load demand while maintaining voltage regulation and operational stability. These findings validate the robustness and effectiveness of the proposed energy management strategy in addressing the challenges associated with renewable energy intermittency in islanded DC microgrid systems.