A real-time smart charging station for EVs designed for V2G scenario and its coordination with renewable energy sources

In this paper, a real-time smart charging station (CS) for charging and discharging of electric vehicles (EVs) has been presented. The proposed CS is coupled with renewable energy sources to support and stabilize grid operations at all times. The main focus of this paper is to illustrate the interaction between various entities such as-CS, EVs, and renewable energy sources. EVs act as controllable loads which can be efficiently utilized to store the excess energy generated from the renewable energy sources during off-peak hours. During peak hours, EVs manage voltage fluctuations by discharging their stored energy back to grid. This bi-directional flow of power is utilized to cater the intermittency issues caused by renewable energy sources. In addition to it, a fuzzy logic controller (FLC) has been designed to regulate the flow of power between the grid and EV's batteries. Also, EVs' batteries are made to charge and discharge based on various constraints such as-minimum state of charge (SoC) and charging rate (Crate). In short, regulated coordination between EVs and CSs plays a potential role in regulating voltage fluctuations at grid level besides handling the intermittency issues of renewable energy sources. The proposed scheme has been modeled and tested on a distribution grid of a city where its performance is found satisfactory with respect to various metrics.