Integration of PV, battery, and a hydrogen electrolyzer with different grid-forming and grid-following control strategies

Abstract

This master’s thesis presents the modeling and simulation of a microgrid system integrating a photovoltaic array, a battery energy storage system, and a hydrogen electrolyzer. Each subsystem is connected via power electronic converters operating under either grid-forming or gridfollowing control strategies. The main objective is to assess the dynamic behavior of these control approaches under various grid strength conditions, defined by the Short-Circuit Ratio (SCR). Different voltage control strategies are implemented for the grid-forming control: conventional voltage control, virtual impedance, and virtual admittance. Through realistic simulation scenarios, this work evaluates stability, transient response, and power-sharing capabilities of each strategy. Results indicate that while traditional control methods are more prone to oscillations, virtual impedance and admittance improve robustness in weak and low-inertia grids. Virtual admittance offers better stability at the cost of slower response, whereas virtual impedance allows faster dynamics with a trade-off in robustness. This work contributes to the understanding of how to properly select and tune control strategies for resilient and flexible future microgrids.