Implementation of a robust droop control for the primary control of a low inertia AC microgrid

Abstract

In isolated microgrids, precision and stability are important criteria for ensuring the production-consumption balance between different equipment, and are also essential for optimising the integration of renewable energies. These criteria not only extend the operating range of systems, but also guarantee optimal operation of microgrid equipment. Against this background, this research proposes advanced approaches to decentralized control, including robust droop control (RDC). The objective of this method is to guarantee precise, balanced power distribution between two grid-forming inverters (GFIs) operating in parallel. These devices feed linear resistive and inductive loads connected to the point of common coupling (PCC) of an isolated AC microgrid, operating at base voltage. To compare and confirm the effectiveness of the suggested method, conventional droop control (CDC) is also implemented for reference purposes. A Matlab/Simulink simulation validates our proposal. The RDC controller improves robustness, power sharing accuracy and stability compared with the conventional CDC. In both transient and steady-state conditions, both methods demonstrate their effectiveness, particularly during load variations. The RDC optimizes power sharing accuracy, reduces frequency oscillations and fluctuations, enhances the dynamics, robustness, accuracy of power distribution, and stabilizes voltage with less oscillation.