Distributed Resilient Secondary Control for AC Microgrids Against Hybrid Attacks

In this paper, the distributed secondary voltage and frequency restoration problem is addressed in AC microgrid systems subjected to hybrid false data injection (FDI) and denial-of-service (DoS) attacks. Firstly, a new distributed resilient iterative estimator based on the k-step estimation method is proposed that can accurately estimate the FDI attack signals as well as the voltage and frequency of each distributed generation (DG) even under the impact of DoS attacks. Then, based on the mean value of the attack estimation signal, a distributed resilient secondary controller is designed to compensate for the considered hybrid attacks. Compared with existing researches on resilient control of AC microgrids under hybrid attacks, the voltage and frequency regulation errors of the microgrid system converge to zero for the first time. Finally, the precise convergence of voltage and frequency in the AC microgrid system under the proposed method is verified through a real-time controller-hardware-in-the-loop experiment in OPAL-RT.