A Distributed Finite-Time Control for Islanded AC Microgrid with Communication Delays

A novel distributed finite-time secondary control is proposed for both accurate voltage/frequency restoration and power sharing of the islanded AC microgrid (MG) with droop-controlled inverter-based distributed generators (DGs). DGs in the islanded AC MG only utilize local information and their neighbor’s information to make the proposed consensus-based finite-time secondary control fully distributed. By contrasting with other finite-time secondary controls, the most highlighted contribution of this work is that the upper bound of communication delay of the islanded AC MG under the designed finite-time secondary control can be solved by the linear matrix inequality (LMI) method. Finally, the good performance of the proposed control framework against large communication delay is evaluated in the Simulink of MATLAB toolbox.

I. Introduction

Microgrids (MGs) are small electrical systems consisting of many different DGs, energy storage devices and multiple loads. It can operate in the grid-connected or islanded modes [1–2]. Because the power rating of the primary grid is much larger than MG, the dynamics of the grid-connected MG is dominated by the primary grid and its control is easy to design. However, because of lacking the frequency/voltage support from the power grid, the control of the islanded AC MG is more difficult to be designed [3]. It means that the studies about the control of the islanded MGs is worthy.