The emphasis on clean and green technologies to curtail greenhouse gas emissions due to fossil fuel-based economies has originated the shift towards electric mobility. As on-road electric vehicles (EVs) have shown exponential growth over the last decade, so have the charging demands. The provision of charging facilities from the low-voltage network will not only increase the distribution system’s complexity and dynamics but will also challenge its operational capabilities, and large-scale upgrades will be required to meet the inevitably increasing charging demands. An ultra-fast (UF) charging infrastructure that replicates the gasoline refueling network is urgently needed to facilitate a seamless transition to EVs and ensure smooth operation. This paper presents a review of state-of-the-art DC fast chargers, the charging infrastructure’s current status, motivation, and challenges for medium-voltage (MV) UF charging stations (UFCS). Furthermore, we consider the possible UFCS architectures and suitable power electronics topologies for UF charging applications. To address the peak formation issues in the daily load profile and high operational expenses of UFCSs, integration of renewable energy sources and energy storage systems due to their technological and economic benefits is being considered. The benefits of line frequency transformer (LFT) replacement with a solid-state transformer (SST), SST models, SST-based UF chargers, and MV SST-based UFCS architectures, as well as related MV active front-end and back-end power electronics topologies, are presented. Finally, the application of microgrids’ hierarchical control architecture is considered for chargers and system-level control and management of UFCSs.

中文翻译：

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超快速充电站中压并网概述：现状与未来趋势


由于基于化石燃料的经济体对清洁和绿色技术的重视，以减少温室气体排放，引发了向电动汽车的转变。随着道路电动汽车 (EV) 在过去十年中呈指数级增长，充电需求也呈指数级增长。低压电网提供充电设施不仅会增加配电系统的复杂性和动态性，也会对其运营能力提出挑战，需要大规模升级以满足不可避免增加的充电需求。迫切需要复制汽油加油网络的超快速（UF）充电基础设施，以促进向电动汽车的无缝过渡并确保平稳运行。本文回顾了最先进的直流快速充电器、充电基础设施的现状、动机以及中压 (MV) 超滤充电站 (UFCS) 面临的挑战。此外，我们还考虑了适用于 UF 充电应用的可能的 UFCS 架构和合适的电力电子拓扑。为了解决UFCS的日常负荷曲线和高运营费用的峰值形成问题，由于其技术和经济效益，可再生能源和储能系统的集成正在被考虑。用固态变压器 (SST) 替代工频变压器 (LFT)、SST 型号、基于 SST 的 UF 充电器、基于中压 SST 的 UFCS 架构以及相关中压有源前端和后端的优势提出了电力电子拓扑。最后，考虑将微电网的分层控制架构应用于充电器和UFCS的系统级控制和管理。