Distributed Observer-Based Resilient Control of Cyber-Physical DC Microgrids Against Communication-Link and Local Attacks

This paper presents a distributed observer-based resilient control (DORC) scheme to mitigate false data injection attacks (FDIAs) in cyber-physical DC microgrids, including communication-link attacks among distributed generations (DGs), and local attacks on measurement and control signals of DG. In the DORC scheme, physical layer and cyber layer of DC microgrid are modeled and combined into an integrated cyber-physical model. Considering the fact that communication-link attack will propagate in DC microgrid and affect the physical-link dynamics among DGs, a new communication-link signal is introduced in the secondary control of microgrid to unify the physical-link and communication-link dynamics for model integration. Based on the integrated model, cyber-physical attack observer (CPAO) is constructed for each DG to directly estimate the communication-link and local attack signals based on unknown input estimation method. The attack estimations provided by CPAO are fed back to control loops to compensate the faulty signals, and the secondary control gains of DG are designed to mitigate the attacks on different locations. The proposed DORC scheme can realize the cooperative voltage control of DGs and ensure the resilient operation of DC microgrid under communication-link and local attacks. The effectiveness and performance of the proposed DORC scheme is demonstrated by simulation cases that compares with a trust-based cooperative control scheme, and it is further demonstrated on an experimental testing platform.