  This paper proposes a cyber-resilient distributed control strategy equipped
with attack detection capabilities for islanded AC microgrids in the presence
of bounded stealthy cyber attacks affecting both frequency and power
information exchanged among neighboring distributed generators (DGs). The
proposed control methodology relies on the construction of an auxiliary layer
and the establishment of effective inter-layer cooperation between the actual
DGs in the control layer and the virtual DGs in the auxiliary layer. This
cooperation aims to achieve robust frequency restoration and proportional
active power-sharing. It is shown that the in situ presence of a concealed
auxiliary layer not only guarantees resilience against stealthy bounded attacks
on both frequency and power-sharing but also facilitates a network-enabled
attack identification mechanism. The paper provides rigorous proof of the
stability of the closed-loop system and derives bounds for frequency and power
deviations under attack conditions, offering insights into the impact of the
attack signal, control and pinning gains, and network connectivity on the
system's convergence properties. The performance of the proposed controllers is
illustrated by simulating a networked islanded AC microgrid in a Simulink
environment showcasing both attributes of attack resilience and attack
detection.
