Experimental Characterization of a 750-V 100-kW 16-kHz Bidirectional Isolated DC-DC Converter With a Unity-Turns-Ratio Transformer at Different Voltage Ratios

This paper focuses on precise conversion-efficiency measurement of a bidirectional isolated dc-dc converter using the 1.2-kV 400-A SiC-MOSFET/SBD H-bridge modules, along with a unity-turns-ration transformer. A specially-designed test bench for efficiency measurement is characterized by the cascade connection of the two identical 750-V 100-kW 16-kHz bidirectional isolated dc-dc converters. Although the test bench is equipped with two identical unity-turns-ratio transformers, both converters are capable of operating at different voltage ratios ranging from 0.87 to 1.13. Experimental results verify that the whole conversion efficiency from the dc input to the dc output is as high as 98.9% at the rated power of 100 kW with a voltage ratio of 1.13, and 98.6% at 100 kW with another voltage ratio of 0.87, excluding an auxiliary power loss of 82 W.