Modeling of an Off-Grid Stand Alone Solar PV with Battery Backup System for an Isolated Rural Area

The increasing demand for renewable energy sources has driven significant advancements in solar PV technology. Stand-alone PV systems, which operate independently of the grid, are especially vital for remote areas where grid access is infeasible. This paper presents a performance analysis of an independent PV system featuring battery backup, leveraging Simulink for real-time monitoring and control. Integrating a PV array and a battery storage unit connected to a constant voltage single-phase AC supply, the system was implemented using MATLAB Simulink across seven distinct operating modes. The bidirectional DC-DC converter is designed to operate in buck mode for charging and boost mode for discharging. It is under the control of an advanced Battery Management System (BMS) to enhance efficiency and prolong the battery's lifespan. Notably, the system maintained a stable DC bus voltage of around 375 V, with minor initial fluctuations quickly stabilized, ensuring efficient power management with an overall efficiency exceeding 90% under varying environmental conditions. The system efficiency was increased by up to 25% by integrating various Maximum Power Point Tracking (MPPT) methods to deal with fluctuating irradiance levels. The real-time response, with mode transitions occurring under 200 msec, highlights its continuous and stable power delivery capability. The PV monitoring dashboard feature provides real-time parameter visualization and interactive control, allowing dynamic observation of mode transitions and demonstrating the capability to maintain stable operation and efficient power management under varying conditions. This study demonstrates a robust solution for stand-alone PV applications, ensuring efficient BMS and prolonged battery life.