Studies have shown the efficiency benefits of DC dis- tribution systems are largely due to the superior performance of DC/DC converters. Nonetheless, these studies are often based on product data that differs widely in manufacturer and operating voltage. This work develops a rigorous loss model to theoretically compare the efficiency of a DC/DC and an AC/DC PFC boost converter. It ensures each converter has the same components and equivalent operating voltages. The results show AC boost converters below 500 W to have 2.9 to 4.2 times the loss of DC.

DC microgrids have become a prevalent topic in research in part due to the expected superior efficiency of DC/DC converters compared to their AC/DC counterparts. Although numer-ous side-by-side analyses have quantified the efficiency benefits of DC power distribution, these studies all modeled converter loss based on product data that varied in component quality and operating voltage. To establish a fair efficiency comparison, this work derives a formulaic loss model of a DC/DC and an AC/DC PFC boost converter. These converters are modeled with identical components and an equivalent input and output voltage. Simulated designs with real components show AC/DC boost converters between 100 W to 500 W having up to 2.5 times more loss than DC/DC boost converters. Although boost converters represent a fraction of electronics in build-ings, these loss models can eventually work toward establishing a comprehensive model-based full-building analysis.