Digital substations - the backbone of smart grids

As reported on a worldwide, there is a tendency to develop and implement smart substations, which basically change every single aspect of the well-known technological processes of production, transmission and distribution of electrical energy. Usually, the implementation of an intelligent substation is achieved by implementing intelligent primary high-voltage equipment and complex secondary devices subordinated to a hierarchical structure. Functional connections, information exchange and interoperability among the multitude of implemented intelligent modules is provided based on the IEC 61850 communication protocol. This report examines the main elements of each digital substation (DS), the international standards that relate to the construction and operation of the DS, and the types of structures related to the information flows in the DS.