Resonant Dual Active Bridge Partial Power Converter for Electric Vehicle Fast Charging Stations

Abstract

This paper presents an analysis and design of a DC-DC charging unit for an electric vehicle fast charging station. Due to the benefits that partial power processing achieves in terms of size reduction and efficiency improvement, it is decided to implement a partial power converter architecture. This type of architectures reduce the power to be processed by the converter, but they require an isolated topology. Therefore, a dual active bridge series resonant converter is selected for the study due to its benefits in terms of soft switching conditions. Design wise, it is decided to ensure zero voltage switching at the secondary side of the converter. Indeed, one of the benefits of the implemented partial power converter is the reduced voltage that exists at the primary side. This way, lower voltage overshoots and switching losses are expected. Finally, via simulations, it is confirmed that partial power processing can be achieved with a resonant converter and that zero voltage switching operation is ensured at the secondary side through the entire charging process.