Design of a PV Based Power Supply with a NonInverting Buck-Boost Converter

Abstract

This paper presents the design of a photovoltaic based power supply using a non-inverting buck-boost converter to charge batteries. The batteries can be used to power a load as back-up power when there is no sunlight. This approach presents a constant output of 48 V charging voltage for the batteries even though the input voltage may vary depending on the amount of solar irradiation falling on the solar panel. Solar charge controllers are important components in such an off-grid system because they can be used to protect the battery bank from overcharging and regulate the charging current. The buck-boost converter is used as a solar charge controller to maximize the charging voltage when the solar irradiation provides less than the required output voltage. The DC-DC converter (buck-boost converter) was modelled using the SIMetrix software to demonstrate the expected output waveforms before building the complete PV power supply.