Analysis of protection issues in autonomous MV micro-grids

The paper focuses on the study of the protection problems arising in a MV autonomous micro-grid starting from the analysis of its physical and electrical characteristics in order to asses through numerical simulations how they influence the design of suitable protection schemes. From the viewpoint of distribution operators, it is advisable for technical and economical reasons to consider as far as possible protection devices based on the same principles used for fault clearing and isolation in a traditional distribution network, bearing in mind that any micro-grid protection scheme has to be compatible with the general scheme implemented in the main MV distribution system to which the micro-grid is connected.