Co-Event-Triggered Estimation and Control for DC Microgrids With Distributed Switching Encryption: Privacy Guarantees Under Active Eavesdropper

This paper studies the privacy-preserving current-sharing control of distributed generation units (DGUs) in DC microgrids under active eavesdroppers, who not only leak data privacy but also disrupt communication. To address the issues of control performance loss and neighbor agreement encountered in existing privacy-preserving control strategies, a novel distributed switching encryption is proposed. For different communication links, the DGU adopts different encryption signals, which intermittently switch to avoid being cracked. Then, a self-decryptor is provided in each DGU to recover the received masked data with a combinational identification approach. On this basis, the distributed observers and controllers with self-decryptors are collaboratively designed to optimize the anti-disturbance performance against tie-line currents and tolerate the communication disruption of active eavesdroppers. Furthermore, a co-event-triggered mechanism is developed to reduce the communication frequencies among DGUs and the updates of buck converters. Finally, the effectiveness and advantages of the proposed current-sharing scheme are illustrated by the simulation results.