Global power sharing and virtual inertia control for the interlinking modular universal converter in standalone hybrid ac/dc microgrid

• Hierarchical control strategy enables zero-error global power sharing in standalone hybrid ac/dc microgrids. • Adaptive bidirectional virtual inertia improves both frequency and voltage stability under dynamic loading. • Implementation on a modular universal converter ensures high flexibility and voltage boosting capability. • Hardware-in-the-loop experiments validate dynamic performance and robustness of the proposed method. • Extended control functionalities support coordinated operation of distributed generators during islanded mode. Hybrid ac/dc microgrids (HMGs) have gained significant attention in recent years for their efficient integration of distributed energy resources and their capability to operate independently from the grid during islanded mode. The bidirectional interlinking converter (BIC) is the key element that coordinates power exchange between sub-grids to achieve precise power sharing. This work introduces a hierarchical control strategy providing adaptive bidirectional virtual inertia (BVI) support and precise global power sharing in a standalone HMG. Besides, the proposed control strategy was designed and validated for the recently introduced modular universal converter (MUC) topology with voltage boosting capability, demonstrating its effectiveness in performing advanced BIC functionalities such as inertia support. The hardware-in-the-loop tests conducted in real time show that the proposed strategy achieves zero power sharing error while enhancing the voltage and frequency stability through BVI transferring. Furthermore, the performance of the MUC as BIC with advanced functionalities is demonstrated, reaffirming its strong potential as a highly modular and standardized power converter solution for standalone HMGs.