Photovoltaic Microinverter Based on Buck-Boost Converter and Discharge Circuit

This paper presents a novel topology for photovoltaic microinverters that uses a buck-boost converter coupled with a discharge circuit. The system enables efficient conversion of electrical energy from the solar panel without requiring voltage filters or step-up transformers. For its control, an exponential action control strategy is used, as it allows effective tracking of the reference voltage. The stability of the overall control and inverter system is demonstrated and detailed using the Lyapunov method. The sizing of the components used is also detailed. The performance of this topology is evaluated under various load conditions, revealing low harmonic distortion (THD) in both current and voltage, with the best THD of 1% being obtained at a power factor of 0.8. This makes it a promising solution for photovoltaic energy conversion. © 2024 Budapest University of Technology and Economics. All rights reserved.