High Efficiency, High Power Density 10kW Flying Capacitor Converter Based on 650V GaN for 800V EV Applications

In this paper, a high-efficiency and high-density 800V, 10 kW three-level flying capacitor multilevel (FCML) converter with 650V GaN devices is analyzed, designed, and tested. Several modern publications in high-density FCML concentrate on using a large number of levels. Despite the benefits of using many more levels, they add to the design complexity and cost of the converter. However, three-level FCML, which has lower complexity of design as well as control and consists of fewer switches is not studied enough for high-efficiency and high-power-density converters. To fill the gap, this paper intends to present a high-efficiency and high-power-density 800V all-GaN FCML. Also, since the inductor of the FCML is one of the bulky and dissipative components in the circuit, an optimized matrix-inductor is presented. The designed converter is tested to 10kw and achieved a peak efficiency of 98.9 % and power density of 271.2 W/in ³ (16.54 kW/L) including the fan and heatsink.