Distributed Robust Secondary Control of Islanded Microgrids: Voltage, Frequency, and Power Sharing

In this paper, a novel distributed robust secondary control is proposed to restore both voltage and frequency in islanded inverter-interfaced microgrids (μGs). The proposed method is superior particularly in the disaster ex-post resilient islanded operation of μGs where various unknown disruptions and uncertainties exacerbate the successful operation of conventional control schemes. Accordingly, the proposed control scheme is devised so as to accommodate the nonlinearity of μG and non-ideality of communication networks such as time-varying delays, data packet losses, and link failures. For μG voltage control, a distributed robust algorithm based on a model predictive control is developed. To do so, the Lyapunov-Razumikhin functional is exploited to analyze the stability of the proposed method, and sufficient conditions are then speculated by the linear matrix inequalities technique. For μG frequency restoration and achieving accurate active power sharing, a finite-time distributed robust proportional-integral algorithm is presented. The effectiveness of the proposed method is verified by inclusive simulation studies of an islanded μG in MATLAB/ Simulink.