Modular photovoltaic inverter with high-frequency DC/DC stage based on low-voltage FETs

Abstract

This paper proposes a multi-string DC/AC architecture for photovoltaic grid-connected converters intended using GaN FETs as switching devices. Three isolated DC/DC converters fed by separate strings supply the DC Link of a 7-level cascaded H-Bridge DC/AC multilevel inverter. Due to the great interest in power plants oriented to selfconsumption, a DC/DC converter configuration with a battery system for energy storage is also considered. Extensive simulations of the control confirmed the capability of the architecture to handle the power flows required by the proposed application.