Advanced Droop Control Strategies for Microgrid

This article reviews the current landscape of droop control methods in Microgrids (MG), specifically focusing on advanced, communication-less strategies that enhance real and reactive power sharing accuracy. While widely utilised, Conventional Droop Control (CDC) techniques often struggle with power sharing inaccuracies and dynamic response inefficiencies, particularly in systems with resistive, complex or mismatched line impedances. This review introduces a novel and systematic classification of advanced droop control strategies aimed at addressing these limitations. The proposed classification categorizes methods based on their ability to improve power-sharing precision in different scenarios, including Low-Voltage (LV) MGs with resistive lines, Medium-Voltage (MV) systems with complex feeder impedances, dynamic loading conditions, and mismatched line impedance scenarios. For example, virtual impedance-based droop methods enhance reactive power sharing in mismatched impedances, while reverse droop control improves power sharing in resistive LV networks. Power decoupling transforms are also employed to enhance power-sharing precision in complex and resistive MG. This review also provides an in-depth analysis of the CDC, with its limitations verified through extensive simulations. A comparative study of advanced droop methods based on key parameters clearly explains their applicability in various operational scenarios. The findings are validated through simulations, providing practical insights into using advanced droop control methods in MG.