Protection, Communication and Topology Aspects of an Electrical Underground Distribution Grid

The Research and Development project named Urban Futurability, developed by the energy distribution utility Enel Distribuição Sao Paulo, has as its initiative to bury and modernize part of the overhead electric power distribution grid, applying an intelligence layer to a pilot grid located in São Paulo, Brazil. This paper deals with the electrical aspects and the main innovation points in the protection and communication systems adopted in the respective underground distribution grid. The designed grid has a radial configuration with automated switches spread over underground Medium Voltage (MV) feeders, which ensure the segmentation of the distribution network. This way, the Supervisory Control and Data Acquisition System (SCADA) receives the information from the communication and protection layers, to ensure greater reliability and flexibility in the grid operations. These assets contribute to the gradual migration to a model of intelligent functionalities, allowing the power utility to improve its essential services, bringing benefits to the consumer population, without compromising the system.