Generalized Analysis of the Performance of DAB Converters for Modular Heavy-Duty EV Charging Stations

Abstract

The commercialization success of heavy-duty electric vehicles (EVs) is predominantly contingent upon the development of a robust and scalable charging infrastructure. Compared with low-frequency transformers (LFT), modular applications of solid-state transformers (SST) offer a more promising solution for achieving MW-level power scalability in the future. In the DC/DC stage of SSTs, the dual active bridge (DAB) converter is a widely adopted topology. And the optimal modulation plays a crucial role in selecting appropriate switching devices and improving overall efficiency. This paper focuses on the specific case of a 33.3 kW module within the modular charging station for heavyduty EVs, presenting a generalized approach to optimize the current stress of MOSFETs and soft-switching performance. The switching performance of the candidate devices for this case has also been quantitatively discussed and verified to achieve soft switching over a wide load range in PSIM simulation.