A CONJUGATE GRADIENT CONTROL METHOD FOR GRID-TIED PV SYSTEMS SUPPORTING DISTORTION-FREE, CONTINUOUS BIDIRECTIONAL EV CHARGING

Abstract

This work proposes an advanced control strategy for a grid-connected photovoltaic (PV) system enabling continuous and distortion-free bidirectional electric vehicle (EV) charging. The system integrates a standalone solar PV array with an AC grid through a multifunctional voltage-source converter (VSC), while the EV battery interfaces with the DC bus of the converter. To achieve robust power regulation and superior power quality, a novel adaptive controller based on the conjugate gradient method is developed. The controller dynamically optimizes the switching signals of the VSC to maintain sinusoidal grid currents, minimize harmonic distortion, and support seamless bidirectional energy flow between the grid, PV array, and EV battery. MATLAB/SIMULINK simulations validate the effectiveness of the proposed approach, demonstrating enhanced system stability, improved tracking performance, rapid convergence, and significant reduction in current distortion under changing irradiance and load conditions.