Experimental Analysis on Laboratory DC Fast Charging Architecture for Electric and Plug-in Hybrid Vehicles

This manuscript is aimed to present a complete experimental analysis on DC power architecture for fast charging operations of full electric and plug-in hybrid vehicles. The described research activities start from an experimental characterization of energy storage systems of different technologies during their charging and discharging operations. These tests are carried out through a specific laboratory bench, which is properly controlled in order to obtain the required charging/discharging profiles. Then the analysis on the DC charging architecture is performed by means of a laboratory prototype, which has been designed and realized as case study. The analyzed prototype of DC charging station is composed by a 20 kW grid tied AC/DC converter, which realizes the DC-Link starting from the low voltage AC grid, and DC/DC power converters for the connection of vehicles on charge and stationary energy storage buffers. Experimental tests are aimed in this case to characterize and analyze the performance of the considered DC power architecture in different operative conditions. Laboratory results have firstly shown the good behaviour of lithium storage technologies in supporting fast charging/discharging operations. Then the experimental evaluations on the laboratory prototype have shown the effectiveness of the realized control strategies and the real advantages of using DC charging architecture, integrated with energy storage buffers, mainly in terms of efficiency, charging times and impact on the main grid.