An All-GaN 800V Three-Level PFC Converter

To address the range anxiety issue in battery electric vehicles (BEV), one of the most effective methods is to increase the powertrain voltage. This architecture doubles the charging power at the same current, resulting in faster charging. Today’s on-board chargers (OBC) are designed for 400V power train and has lower power level. This paper discusses the design and implementation of a 22kW, 800V bidirectional DC/AC converter for 800V BEVs. Using gallium nitride (GaN) devices significantly improves the efficiency and power density of the converter. However, there’s a challenge due to the limited blocking voltage of GaN devices when designing for 800V applications. To tackle this challenge, the paper employed a three-level flying capacitor topology system. This bidirectional PFC system achieves outstanding power density of 203.6W/in³.