Hydrogen-PV-Battery System for Hybrid EV Charging Stations with Grid Integration and Islanding Control by using DHOGI-QT2 based PLL

This paper presents a modified versoria zero attraction based least mean square (VZA-LMS) control strategy for a grid-supportive PV-battery system, aimed at hydrogen production and continuous power supply in hybrid electric vehicle (EV) charging stations. The proposed system operates seamlessly in both grid-connected and islanded modes, ensuring uninterrupted power delivery even during grid outages. In grid-connected mode, current control effectively extracts reference grid currents, suppresses harmonics, and enables unbiased parameter estimation under distorted input conditions. In islanded mode, voltage control ensures reliable power supply to the electrolyzer and local loads via the PV-battery system. The system features harmonic current suppression, load balancing, reactive power compensation, and power factor correction. A PV feed-forward loop maximizes power extraction from the PV array and feeds it into the utility grid. Simulation and experimental results validate the system's capability to transition smoothly between grid-connected and islanded modes while meeting IEEE-519 standards for total harmonic distortion (THD). The proposed control strategy demonstrates reliability and efficiency under varying operational conditions, making it an effective solution for hydrogen production and EV charging in both off-grid and grid-connected environments.