The Role of Bidirectional Electrical Vehicle Chargers in Enhancing Variable Renewable Energy Integration into the Electric Grid

Abstract

The rise in electric vehicles (EVs) and Variable Renewable energy sources such as solarand wind has introduced both opportunities and challenges for the modern power grid.The variability of Variable Renewable energy and the growing electricity demand from EVs strain the grid's capacity.This thesis proposes a bidirectional EV charger system integrated into the grid that enables both Vehicle-to-Grid (V2G) and Grid-to-Vehicle (G2V) operations.By using EV batteries as distributed energy storage units, the system balances energy flows between EVs, Variable Renewable energy sources, and grid demand.A detailed system design is developed and simulated using MATLAB/Simulink under various grid conditions, including peak demand periods, low and high Variable Renewable energy generation, and diverse load profiles typical in urban environments such as Vienna, Austria.The system includes an advanced Energy Management System (EMS) that dynamically manages energy flows between the grid, Variable Renewable sources, and EVs.Key results show that integrating bidirectional EV chargers into urban power grids significantly enhances grid stability, improves the utilization of Variable Renewable energy, and mitigates peak load impacts.The system also helps prevent curtailment of Variable Renewable energy and provide sancillary services such as frequency regulation and voltage support. Additionally, a cost benefitanalysis shows that while initial investments in bidirectional chargers and infrastructure are high, the long-term benefits, including grid flexibility and carbon footprint reduction, outweigh the costs.This thesis also provides recommendations for deploying V2G technologies in urbansettings, considering regulatory, economic, and technical challenges.