Distributed Finite-Time Secondary Control of Islanded Microgrids by Coupled Sliding-Mode Technique

This paper deals with the problem of voltage and frequency restoration in droop-controlled inverter-based islanded microgrids (MGs). The problem is solved using a novel tracking consensus secondary control protocol based on the sliding-mode approach, which not only guarantees the exact finite-time restoration among voltages and frequencies of an inverter-based islanded microgrid, but also preserves the active power sharing among distributed generations (DGs). For each distributed generator with no direct access to reference values, a finite-time distributed estimator is locally designed and implemented in each DG unit to provide the reference value of frequency and voltage in a finite time. Lyapunov analysis is employed to verify the associated stability and fast convergence time of the proposed controller. Finally, simulation results are are presented and analyzed to confirm the effectiveness of the proposed approach.