Simulation of Solar Charge Controller Module with Current Backflow Protection

Solar energy is popular worldwide due to the escalating demand for renewable and clean energy solutions. The inherent low power conversion efficiency of solar panels highlights the indispensable role of a solar charge controller in optimizing the power transfers from the solar panel to a storage battery. Traditional buck converters are marred by considerable power losses due to freewheeling diodes, thus making a synchronous buck converter, which necessitates protection against the reverse current from the battery to the solar panel. During low irradiation, the solar panel voltage typically falls below the battery voltage, creating the potential for reverse current flow, which may cause damage to other system components. This study proposes an innovative current backflow protection circuit, effectively addressing reverse polarity risks, demonstrated through LTspice simulations. Utilizing an NMOS MOSFET, this circuit disrupts the connection whenever solar panel voltage falls beneath a predefined cutoff value, thereby preventing reverse current damage. The protective mechanism’s efficacy is validated by monitoring the NMOS MOSFET’s drain current, which remains at 0A below the cutoff voltage but transitions to negative values above it, indicating a reverse flow and underscoring the circuit’s reliability in safeguarding solar energy systems.