DESIGN AND SIMULATION OF AN ELECTRIC VEHICLE CHARGER FOR SUSTAINABLE TRANSPORTATION

Abstract

In recent years, electric vehicles have become increasingly popular due to growing concerns about climate change and the limited availability of fossil fuels. The battery charging system is a crucial component of electric vehicles, and it has received significant research attention, particularly in relation to vehicle-to-grid (V2G) power transfer. The primary objective of V2G is to facilitate peak load leveling for the grid and serve as a buffer for surplus renewable energy. This thesis focuses on single-phase on-board bidirectional chargers designed specifically for electric vehicle applications. The key areas of investigation include the design, control, and detection of islanding conditions in these chargers. This research entails a comprehensive examination of two different EV charging systems: one based on bidirectional power flow and other for unidirectional. The study involves an optimized design approach for both converters, which accurately assesses the high-frequency current ripple and damping resistor losses. The thesis also covers the design, simulation, and experimental validation of the controllers used in both converters. This study also focuses on examining the influence of 3rd harmonics on the performance of second-order generalized integrator (SOGI) phase-locked loops (PLLs). An analytical approach is used to predict the magnitude of the output harmonics that result from this impact. To enhance the harmonic rejection performance, two modified SOGI PLLs are introduced in the research. A 1KW and a 2KW prototype of the EV charger have been designed and simulated using MATLAB/Simulink. At full load, the power factor achieved is 0.999 with a THD under 5%.