Research Projects

India is one of the largest car markets globally, and for the reasons mentioned above, it is moving towards Electric Vehicles (EV). Out of some research challenges, developing a proper EV charging infrastructure is a primary area. Creating a high-performance yet very convenient and safe EV charging station is essential, attracting customers and switching from conventional vehicles to EVs on a large scale. Typically, EV carries a battery pack that has poor energy density and requires a long charging time. DC Level-3 fast charging is gaining importance due to its charging time being comparable to the refuelling time in ICE-based vehicles. DC Level-3 chargers have a power rating of 100-250 kW and even more in recent years. An on-board charger would not be able to manage that much power. It also leads to heavier and more expensive vehicles. The off-board chargers are desirable to implement the high-power DC fast chargers in a charging station. The grid stability can also be maintained by the integration of battery energy storage (BES) and renewable energy in the charging station. Several private and government organization has already developed charging station with DC fast charge and integration of battery energy storage and renewable energy. However, the existing charging station have used bulky grid frequency transformer (GFT) to step down medium AC voltage to low AC voltage and then AC-DC converters, due to which the power density of such system is very low (0.2 kW/L). Moreover, the installation space near metro city is another constrain. Therefore, in this proposal an architecture of Solid-State Transformer (SST) based medium voltage (11 kV) grid connected EV charging station with DC-fast charger and integration of battery energy storage and renewable energy will be develop. The novelty of the proposed charging station will be: (1) multilevel converter based single stage SST which will convert 11 kV AC voltage to 1kV DC voltage (DC-bus). (2) the overall the power density of the proposed charging station will be 3 kW/L (or even more). (3) the grid stability will be maintained by the integration of battery energy storage (BES) and renewable energy in the proposed charging station (3) a smaller number of AC-DC and DC-DC conversion steps will be use. (4) less numbers of components and smaller magnetics will be use in proposed system. (5) robust control algorithm will be developed to achieve all required modes (V2G, G2V, PV to EV/grid, BES2G and G2BES) of operation of proposed charging station. To show the effectiveness of proposed EV charging station, a 350-kW system will be developed with following specification 11 kV grid voltage, 1 kV DC bus, DC-fast charger, PV and BES integration in MATLAB/Simulink environment. However, due to academic laboratory limitation a 10-kW laboratory prototype will be developed with following specification 415 V grid voltage, 800 V DC bus, DC-fast charger, PV and BES integration.