Fast Charging Station for Electric Vehicles Based on DC Microgrid
Authors: Harshita Arya and Moumita Das
Extended Abstract:
As the Electric Vehicle sector is growing rapidly, the demand for charging stations is also increasing with the advancement of electric vehicles. Due to EV, the power demand increases in the household as well as the industrial/commercial purposes. The required power in the charging station is very high. The power demand is even higher in a fast-charging station. In the fast charging, the sudden high-power demand causes voltage instability, power loss, harmonic distortion and transformer overloading on the distribution grid. Hence, this work focuses on, firstly to investigate the fast-charging impact on the grid. Secondly, to provide a solution by integrating renewable energy sources (such as solar PV) along with a battery in dc bus to reduce this effect. The proposed system also facilitates bidirectional power flow from grid to vehicle and vehicle to grid. The two types of charging algorithm multi-stage constant current (CC-CC-CC) and multi-stage constant current constant voltage (CC-CC-CV) are implemented with respect to SOC level of the battery to fast charge the electric vehicles. The SOC estimation is also implemented for the fast charging using the fast-charging algorithms and implemented in the fast-charging unit. The control method of various modes of a fast-charging station with and without presence of a solar PV are presented. The simulation results of the proposed algorithm validates various modes of operation for the fast-charging operation. Hardware prototype is developed in the laboratory to validate the proposed charging method in a DC microgrid environment.
