Optimal power extraction and voltage regulation in standalone photovoltaic system

Introduction Reliable electricity in remote regions requires standalone photovoltaic (SAPV) systems, which operate without grid support. However, solar energy fluctuation due to irradiance and temperature significantly affects power generation. Maximum Power Point Tracking (MPPT) techniques are essential to ensure that PV panels operate at peak power under changing environmental conditions. This work integrates a Perturb & Observe (P&O) MPPT algorithm with a Proportional-Integral (PI) controller to enhance power extraction and voltage regulation. Real-time validation is performed using OPAL-RT Hardware-in-the-Loop (HIL) testing to assess performance under dynamic scenarios. Methods A boost converter is designed for an 18 V PV module, boosting the output to around 60 V. The PV system model is developed in MATLAB/Simulink and linked to OPAL-RT RT-LAB for real-time execution. The MPPT controller uses voltage and current measurements to adjust duty cycle, while a PI controller stabilizes voltage near the peak power point. Simulations and HIL testing are carried out under variable irradiance. Results and Discussion Simulation and HIL results confirm voltage boosting with improved stability compared to standalone P&O control. Minor oscillations around MPP are reduced through PI tuning. Efficiency exceeds 95%, demonstrating reliable tracking under varying irradiance. The real-time platform validates design scalability for off-grid deployment.