Improving power sharing and enhancing the stability of an isolated AC microgrid by implementing droop control and virtual impedance

Abstract

The stability and accuracy of power sharing between DGs in isolated microgrids are key points for favouring renewable energy sources within a wider operating margin to extract the maximum available power. The conventional droop control method CDC and the improved virtual impedance droop control CDC-VI are proposed in this work to enhance the stability, improve the speed, robustness and accuracy of power distribution between two parallel DGs feeding three linear loads of different types connected to the AC bus within an isolated AC microgrid. A Matlab/Simulink simulation is carried out to validate our proposal, robustness, accuracy of power sharing between DGs and stability are well improved by the implementation of the proposed CDC and CDC-VI controllers. The main improvements brought by these controllers include improved power distribution with greater precision, enhanced stability even in the presence of disturbances, and faster response in dynamic scenarios. These improvements are crucial to ensuring efficient, reliable operation of microgrids, particularly in isolated environments where integration of renewable energies and management of critical loads are paramount for uninterrupted service continuity.