Design and Analysis of Controller for the Integration of Solar PV and Battery in DC Microgrid for Rural Application

The growing integration of Renewable Energy Sources (RES) in Distributed Generation has significantly enhanced the capabilities and reliability of modern power systems. However, the intermittent nature of solar energy necessitates the use of battery-supported systems to provide additional power backup when needed. The efficiency of a DC microgrid depends on the coordinated control of both DC and AC sources connected to it. This paper presents a DC microgrid topology that integrates Solar Photovoltaic (PV) systems, batteries, and a three-phase AC grid to ensure uninterrupted power system operation. A DC-DC boost converter, integrated with the Perturb and Observe (P&O) algorithm, is used to achieve maximum power point tracking (MPPT) for the solar PV system. Additionally, a bidirectional DC-DC buck-boost converter is employed with the battery to maintain continuous operation despite fluctuations in solar irradiance. A key advantage of this proposed configuration is the reduction in the battery's charging and discharging cycles, thereby extending its lifespan. Furthermore, the DQ control strategy is applied to the active bridge rectifier to ensure unity power factor operation when interfacing with the three-phase grid. The system is modeled and simulated using MATLAB/Simulink, incorporating the design parameters of the boost and bidirectional converters, as well as the solar PV and battery models. The developed controller demonstrates satisfactory performance under both steady-state and dynamic conditions.