A New Medium-Voltage Architecture for Ultra-Fast Electric Vehicle (EV) Charging Stations

Range anxiety and lack of charging infrastructure are the two main barriers to the adoption of electric vehicles (EVs). These concerns can be resolved by using ultra-fast chargers or charging stations. The limitations of the traditional ultra-fast chargers include their low efficiency, high cost, and big footprints, as they are low-voltage (LV) coupled by line-frequency transformers. Researchers suggest the medium-voltage (MV) linked charging station as a solution to the drawbacks of traditional chargers by eliminating the line-frequency transformer and connecting directly to medium voltage. Various medium-voltage multilevel converters have been proposed to permit direct grid connection. However, drawbacks such as a large number of components and control complexity undermine the strength of medium-voltage linked stations. This paper presents a new MV-connected ultra-fast charging architecture that has fewer number components and a lower control complexity in comparison to existing solutions. Moreover, the advantages of MV-connected over LV-connected stations are studied in terms of cost, efficiency, and power quality.