A Decentralized Adaptive Architecture for Resilient Current Sharing in DC Microgrids Under Current Sensor Integrity Attacks

Effective current sharing among distributed generation (DG) units is crucial for microgrid stability, efficiency, and reliability. However, current sensors, which are essential for monitoring and control, might be subject to integrity cyberattacks. This paper develops a novel resilience-enhancing framework based on a decentralized adaptive architecture for current sharing in DC microgrids under integrity cyberattacks in current sensor measurements. The proposed framework employs two key components for each DG unit; a resilient unknown input observer (UIO) and a dynamic virtual current sensor. The proposed resilient UIO and virtual sensors estimate the correct current from inaccurate current sensor measurements and baseline control inputs in the presence of uncertain and unknown load conditions and power lines. Our proposed approach consists of a mathematically rigorous input-output stability analysis. It is shown that the interconnection of the proposed framework with microgrids’ baseline controllers enables DC microgrids to adapt to and compensate for sensor uncertainties without compromising overall performance. Specifically, the augmented framework with the baseline microgrid controller proposed guarantees asymptotic stability of the closed-loop dynamical system under time-invariant current sensor uncertainties and uniform ultimate boundedness under time-varying current sensor uncertainties. Several case studies on a DC microgrid illustrate the efficiency and performance of the proposed resilient current sharing scheme.