An automation for the management of fault events in islanded grids operatated with a ring topology

With the aim to improve the resilience in small, islanded power systems, we suggest their operation according to a ring scheme. To benefit of the advantage of this topological operating mode, it is necessary to equip the ringed power system with smart devices embedding appropriate smart grid functionalities able to perform the fault automation for the self-healing following fault events, i.e. the set of autonomous actions for their detection and isolation. These latter operations should be executed in such a way to preserve the higher continuity and quality of the power supply to the largest number of grid-connected users. In such islanded power systems, characterized by low short-circuit power and inertia, the ringed operating mode, in conjunction with the proposed automation, should also preserve the frequency and voltage stability since the smaller electromechanical stresses experienced by the generating units. Although the study focuses on the islanded power distribution grids, the automation could be adopted also on utility-connected distribution systems to benefit, among other advantages offered by the ring scheme, of the improved continuity of the power supply subsequently to fault events. A demonstrative of the effectiveness of the proposed automation for ringed distribution networks, implemented through proprietary, Gridspertise smart devices has been arranged in a field-like experimental setup.