GaN-Based Interleaved Four-level Flying Capacitor Triangular Conduction Mode (TCM) Converter with Coupled Inductors

Abstract

This study introduces an optimization method that utilizes the adaptive deadtime of the triangular conduction mode (TCM) in an interleaved four-level flying capacitor boost converter with coupled inductors for photovoltaic systems. The operation of the TCM is analyzed for the zero-voltage switching (ZVS) of Metal-Oxide-Semiconductor Field-Effect Transistors (MOSFETs), which is required for high-frequency, high-power-density applications. Coupled inductors, created by combining two inductors from two phases, are employed to enhance the efficiency. Coupled inductors introduce a low current ripple, which improves performance while reducing costs. By analyzing the effect of the coupling coefficient and the relationship between the two inductances on the inductor current ripple and the ZVS model, a suitable coupling structure is recommended for use in the proposed converter. Consequently, design considerations are presented to maximize the advantages of incorporating a coupled inductor in the proposed converter. Finally, a 200W prototype is developed and tested to validate its feasibility.