MPPT Solar Charge Controller with Reverse Current Protection for Efficient PV Systems

Abstract

Solar energy, a vital renewable resource, is harnessed using photovoltaic (PV) systems; however, challenges such as overcharging, component stress and energy losses due to environmental variations compromise reliability and efficiency. While MPPT and reverse current protection have been widely studied, they are often implemented separately, increasing circuit complexity and cost. This research introduces a novel integrated MPPT-based solar charge controller with built-in reverse current protection, providing a unified solution that enhances energy harvesting and system longevity. The controller employs an advanced MPPT algorithm tailored for variable operating conditions and incorporates a protection mechanism that eliminates backflow losses without additional external components. The developed prototype employs two 30–40 W photovoltaic modules connected in parallel to supply the MPPT charge controller. The PV input voltage varies between 12.5 and 20 V depending on solar irradiance, while the controller regulates the battery charging voltage within the safe operating range. Two PV cells, each producing 30–40 W at 14 V, supply power to the controller. Circuit modeling was performed using Proteus software, and real-time validation was conducted with an Arduino Uno. Performance evaluation showed that a duty cycle of 10–14% achieved high conversion efficiency with minimal thermal stress, while a maximum output of 81.47 W was recorded at a 16% duty cycle and 40 °C. Experimental validation demonstrated that the proposed controller successfully eliminated approximately 0.8 A of reverse current during low-irradiance operation while maintaining uninterrupted power delivery to the DC load. By integrating MPPT and reverse current protection in a single design, this work offers a simpler, more reliable, and thermally stable alternative to conventional approaches, contributing to smarter and more sustainable solar energy management in off-grid and hybrid systems.