A distributed finite-time secondary average controller for voltage regulation and power sharing in AC microgrids

This paper proposes a proper hierarchical control strategy composed of a modified droop controller in primary level and a distributed finite-time average controller in secondary layer. The aim of this paper is to achieve precise active and reactive power sharing and frequency and voltage alignment in an islanded AC microgrid (MG). To do so, a typical AC MG is simulated in MATLAB/SIMULINK software, and the proposed method is modeled and implemented. In the simulated AC MG, the distributed generation (DG) units are photovoltaic (PV) systems. The obtained results illustrate that the proposed method appropriately shares active and reactive powers among presented DGs in various operational modes such as load change, increase or decrease in DGs’ output power as well as connection and disconnection of communication links. It also accurately  restores the frequency and voltages of DGs to their nominal values.