Charging Dynamics of LiFePO₄ Batteries Using Concentrated Photovoltaic Arrays: A SIMULINK Approach

We simulated a low-concentration photovoltaic (LCPV) system for charging lithium iron phosphate (LiFePO<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">₄</inf>) batteries. Initially, the short-circuit current I<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">sc</inf> and open-circuit voltage Voc values obtained at a 0° tilt angle were used to determine the optimal series X<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">s</inf> and parallel X<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">p</inf> array configurations required to charge a small LiFePO<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">₄</inf> battery, commonly used in portable solar charging applications. A detailed battery model and a constant current/constant voltage (CC/CV) charging circuit were developed using MATLAB Simulink to simulate realistic charging behaviour. A time constraint was applied to the CC/CV model to evaluate the time required for the concentrated array to reach specific states of charge (SoC), compared to a non-concentrated array. Additionally, the total charging time to reach full SoC (100%) was simulated. Key findings, performance comparisons, and potential sources of error are discussed, highlighting areas for improvement in future concentrator and LCPV system designs.