A new compact on and off-grid inverter for photovoltaic applications

Abstract

A new inverter that have double-outputs based on flying capacitor topology is proposed for photovoltaic applications. The flying capacitor enables the converter to generate three-level output voltages, thus resulting in high-quality output waveforms. The new inverter has fewer semiconductor switches and flying capacitors (up to 25% and 50% less, respectively) than the conventional flying capacitor inverter (FCI) that supplies two loads does. The proposed inverter feeds loads through a photovoltaic system. This inverter can be used in a combined on- and off-grid PV fashion. A control method is developed to maintain the desired flying capacitor voltage. The off-grid section of the inverter can operate under different modulation indices and frequencies, independent from on-grid section. The high performance of the inverter is verified through simulation.