Distributed Fast Fault Detection in DC Microgrids

The problem of distributed fast fault detection for a direct current (dc) microgrid that is composed of multiple interconnected distributed generation units (DGUs) is addressed in this article. A local fault detector is designed for each DGU based on the measured local state of the subsystem as well as the transmitted variables of neighboring measurements, which forms the fault detection network. Indeed, each DGU not only can detect its own fault, but also is capable of detecting its neighbor's faults. Toward this end, a multiobjective optimization problem formulation based on the H_\infty /H_-/ regional pole placement performance criteria is presented and it is solved using linear matrix inequality approach to obtain the parameters of the distributed fault detectors and the optimal amount of the performance indices. The convergence rate of the fault detection observer is improved with the proposed method which leads to fast fault detection in the dc microgrid system. The effectiveness and capabilities of the proposed methodology are demonstrated through a simulation case study.