Performance improvements in a zero voltage switched boost PFC application through the use of SiC power diodes

The use of silicon carbide diodes as alternatives to standard silicon power diodes in a zero-voltage switched (ZVS) 800W boost power factor correction (PFC) converter is examined experimentally. The PFC circuit examined is a part of a base station power supply. Efficiency improvement by using SiC diodes in hard-switched PFC boost power converters has been demonstrated by others, and is considered by many to be an ideal solution. Incorporating SiC diodes in a ZVS topology further improves the performance of the topology. Comparisons are made between ZVS circuits using standard silicon power diodes and an equivalent circuit using SiC diodes. Simplification of the overall circuit, improvement in operating efficiency and improvements in line conducted EMC performance are observed. The paper concludes that the use of SiC diodes in high wattage applications can further improve performance characteristics of ZVS PFC boost converters.