Power Quality Enhancement in Solar-Wind Integrated Grid for Bidirectional EV Charging Using Conjugate Gradient Controller

The growing adoption of plug-in electric vehicles (EVs) has accelerated the demand for reliable and efficient charging infrastructure that ensures stable grid performance. In this context, renewable energy sources such as solar and wind play a crucial role in supporting clean energy supply for EV charging. This paper proposes a grid-connected bidirectional EV charging system integrated with both solar photovoltaic (PV) and wind energy sources. Unlike conventional systems, the proposed architecture emphasizes the contribution of wind power in enhancing overall grid power quality, especially under varying load and generation conditions. The energy from solar and wind is transferred to the grid via a bidirectional voltage source converter (VSC), which manages both active power flow and power quality regulation. To ensure continuous distortion-free operation and compliance with IEEE-519 standards, a Conjugate Gradient Controller (CGC) is implemented for adaptive control of the VSC. The controller effectively improves total system stability, maintains voltage and current profiles, and significantly reduces total harmonic distortion (THD) levels under dynamic conditions. The performance of the proposed system is validated through detailed MATLAB/Simulink simulations, demonstrating its effectiveness in providing stable and high-quality EV charging within a renewable-integrated grid framework.