An Event-Triggered Interval Observer Scheme for Fault Diagnosis of Cyber–Physical DC Microgrids

In this article, we propose an event-triggered interval observer fault diagnosis scheme for cyber–physical dc microgrids. First, a distributed interval observer is designed for each distributed generation unit interconnected by a power line. Then, an adaptive periodic event-triggered mechanism is put forward for saving communication cost. With the bounded fault signal and disturbances, the observer gain and event-triggered parameter can be determined by involving disturbance robustness, fault sensitivity, nonnegativity conditions, and regional pole placement for fast fault detection simultaneously. Based on it, the convergence rate of the state error dynamics can be enhanced to implement fast fault detection. It is shown that the proposed interval observer does not need to develop the residual evaluation function and threshold generator since zero is a natural threshold. The effectiveness and superiority of the proposed scheme are verified through simulations.