Improved Distributed Prescribed Finite-Time Secondary Control of Inverter-Based Microgrids: Design and Real-Time Implementation

The aim of this study is to develop a novel distributed robust prescribed finite-time secondary control for both frequency and voltage restoration along with accurate active power sharing in islanded microgrids (MGs). The prescribed finite-time convergence property irrespective of the values of initial conditions helps to design an offline settling time that leads to power loss reduction. Moreover, thanks to the use of a piecewise-function based approach the upper bound of convergence time is reduced. The fixed-time stability of the proposed scheme is rigorously confirmed by applying the Lyapunov theory, which results in a set of tuning rules. The main challenge is to establish the stability conditions through asymmetrical connections under a directed graph. Finally, the architecture of the experimental setup is constructed for an inverter-based microgrid consisting of six distributed generators (DGs). The OPAL-RT real-time simulator is exploited to verify the applicability of the proposed distributed fixed-time controller.