Advancements in DC Fast Charging for Electric Vehicles: A Review of Architectures, Smart Charging Strategies, and Standards

Abstract

Since the growth of Electric Vehicles (EVs) continues to rapidly gain momentum in the world, there has been a sharp increase in the demand for efficient and smart DC fast charging structures. This paper provides a comprehensive overview of the technologies that contribute to DC fast charging in modern times: system structure and charging standards, as well as the direction of smart charging. In this article, the authors have discussed the choice of different charges, such as wired connection-based charging, battery swapping, and wireless charging, and outlined on-board and off-board chargers in terms of their functions in the existing EV systems. Some of the prominent technical aspects are discussed, like the AC/DC conversion scheme and other DC/DC converter topologies, with emphasis being laid on the isolated or non-isolated design. The idea of distributed energy resources, i.e., solar power and battery storage systems, is brought into discussion on the potential of these resources to facilitate providing grid stability and environmental sustainability. Particular attention is paid to the Open Charge Point Protocol (OCPP), one of the key enablers of the smart charging infrastructure. Starting from the beginning of OCPP to the publication of version 2.1 in 2025, the review describes the history of the development of OCPP as an interoperability enhancer, remote access, load control, and coordinated communication between EVs, charging stations, and energy networks. By consolidating advancements in both technology and standardization, this paper contributes to the growing body of knowledge guiding the evolution of next-generation Electric Vehicle (EV) charging systems.