Through this project, significant strides have been made beyond the state of the art in power electronics systems for EV charging. The research and development have focused on drastically miniaturizing high-power electronics systems for 48 V light EV chargers while enhancing efficiency and performance. The target is not just a technological advancement, but also a substantial contribution to the larger societal goal of promoting sustainable energy practices and reducing carbon emissions. The project's key focus areas include improving converter topologies, control schemes, and optimization techniques, with the objective of elevating the performance of power converters. As such, the project anticipates delivering faster, more reliable, and more efficient charging solutions for EVs. These advancements will enhance the charging experience for EV owners and facilitate the more widespread adoption of electric vehicles.
The power electronic structure at the core of the research comprises a PFC converter and a DC/DC stage. The research has resulted in the invention of a soft-switching TP PFC converter with interleaving legs, contributing to significant advancements in power electronics technology. The project's experimental prototypes have demonstrated impressive power density and efficiency results. For instance, the two-phase interleaved soft-switched TP PFC converter achieved 62 W/in³ and 98.72% efficiency at full load, while the 4-level TP PFC reached 67 W/in³ and 99.2% efficiency. The optimized LLC prototype also showed promising results, with a power density of 45 W/in³ and a peak efficiency of 98.2%.
These achievements have laid the groundwork for extending the developed models to very high-frequency designs. New converter configurations, such as the two-phase interleaved 7-level TP PFC and 3-phase LLC converters, have been analyzed, both utilizing planar magnetics. These high-frequency designs have the potential to further increase power density and efficiency, paving the way for even more compact and advanced power electronics systems. In particular, the 3-phase LLC design with planar magnetics employs an innovative approach known as asymmetrical interleaving. This technique integrates the resonant inductance into the transformer, enabling highly miniaturized designs. All the necessary analyses on the inductors have been conducted, and proof-of-concept prototypes are being manufactured. The 7-Level interleaved GaN-based TP PFC can deliver 3700 watts of power in a compact 255 x 71 x 20 mm form factor using planar magnetics, achieving a power density of 167 W/in³, which significantly exceeds the target of 85 W/in³. When combined with an innovative three-phase LLC with integrated magnetics, the total power density of the system reaches 84 W/in³.
