Electrical engineering

Physics

Battery charger

Electromagnetic coil

Ćuk converter

Flyback converter

Inductor

Engineering

Voltage

Power (physics)

Power density

Electronic engineering

Interleaving

Computer science

Battery (electricity)

Quantum mechanics

Buck–boost converter

Forward converter

Transformer

Boost converter

High voltage

Increased attention is being paid to the solid-state-transformer (SST) based charging station which requires a high efficiency high power density DC/DC stage. This framework would provide universal charging for all electric vehicles (EVs) no matter their battery voltage is 400 V or 800 V. In this paper, a two stage DC/DC converter consisting of a three-phase (3P) CLLC converter and four-phase interleaving Buck converter is proposed to achieve a wide output voltage range from 200 V to 800 V with bi-directional energy transfer capability. With SiC devices, a PCB winding based six-leg integrated transformer is used for the 3P transformer, and a PCB winding based EI core is used for the negative coupling inductors. The detailed design process of integrated magnetics is presented. A 12.5 kW prototype with over 97.7 % efficiency and 100 W/in <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sup> power density is built to verify the feasibility of the proposed structure.

A High Efficiency High Density DC/DC Converter for Battery Charger Applications