Design of a two-switch flyback power supply using 1.7 kV SiC devices for ultra-wide input-voltage range applications

摘要

This paper presents the design and evaluation of a two-switch flyback power supply with ultra-wide input voltage range (230-1300 V), fed from the floating dc bus of power electronics building blocks (PEBB) in medium voltage (MV) modular multilevel converter (MMC) applications. Rated at 80 W, 48 V output, and operating at 50 kHz, the proposed converter uses 1.7 kV SiC devices and a planar PCB-winding transformer to achieve a low-profile form factor. Further, a pre-charge circuit and start-up sequence are developed as well, enabling the two-switch flyback converter to wake up at 230 V. Experimental results are presented for verification and evaluation purposes.