A GaN Based Four-Port Flying Capacitor Multilevel Converter

In this paper, Flying Capacitor Multilevel converter (FCML) topology is used to develop a novel GaN-based four-port multilevel converter. The proposed four-port converter can be used in a variety of applications such as ACgrid integration with Photovoltaic (PV), Energy Storage (ES), and Electric Vehicle (EV). A 5. 7kW prototype with four ports (three DC ports and an AC port) connected through three 4-level FCML conversion paths (one DC-AC path and two identical DC-DC paths) The DC-AC path is capable of processing power of 1.7 kW and incorporates an unfolder for the DC-AC conversion. The DC-AC path has achieved a maximum efficiency of 98.2% with voltage and current Total Harmonic Distortion of 0.78% and 0.71%, respectively. Each of the other two DC-DC paths are capable of processing power of a 2kW and have achieved a peak efficiency of 99.43%.