Development and Validation of an Integrated EV Charging Station With Grid Interfacing Inverter for Residential Application

Abstract

This research paper proposes a novel grid-connected modular inverter for an integrated bidirectional charging station for residential applications. The system is designed to support the electrical grid by providing buffering services and enhancing the stability of the grid. The proposed system consists of a modular bidirectional inverter which can work as an EV charger. The system can operate in different modes such as charging and discharging the EV battery, storing excess energy from the grid during low-demand periods, and supplying energy back to the grid during high-demand periods. A low-level control strategy based on the droop control technique and feedforward decoupling is developed to manage the power flow between the EV battery, household load and the grid. The performance of the proposed system is evaluated through simulation studies in MATLAB/Simulink software. The results show the system's ability to support the grid during peak demand and boost renewable energy integration. It also acts as a backup power supply during outages, increasing reliability. The experimental validation in a laboratory environment confirms an 87% charging efficiency with 35% SoC, drawing 6.3 kW from the grid. Returning power to the grid achieves a V2G efficiency of around 94%, delivering 8.6 kW AC output and 8.77 kW battery input at a 55% SoC.