Experience and Challenges In The Practical Implementation of Four Digital Substations In Brazil

Brazil began its journey towards digital substations in 2006, commencing with implementation of station bus for substation control and supervision, following the IEC 61850 standard Edition 1. Over the years, these implementations have been consistently executed in all projects, currently serving as the standard applied by transmission and distribution utilities. The full application of the IEC 61850 standard, including the implementation of the process bus according to chapter 9-2LE, began in 2014 through pilot projects with three transmission utilities in the southern and southeast of Brazil. These pilot projects had specific goals: (1) experiment with an innovative solution with the technology process bus, (2) evaluate the performance of relay protections connected to the process bus (merging unit, switch, GNSS) versus conventional relay protection connected directly to conventional CT and VT, (3) assess the enhancement in operational safety resulting from replacing copper cables with optical fiber, and (4) evaluate the reduction of investment costs (CAPEX) and operation and maintenance costs (OPEX). The multivendor practical tests of process bus interoperability IEC 61850-9-2LE (Sample values), time synchronization IEEE 1588 PTP V2 and IEC 61850-8-1 (GOOSE) were conducted in 2019 during the first practical demonstration workshop of process bus interoperability in Rio de Janeiro, organized by Cigré Brazil B5 Study Committee. The results and conclusions will be present in this paper. The primary objective of this paper is to review Brazil's journey to digital substations solutions, detailing the experiences and challenges encountered during the practical implementation of four digital substations between 2021 and 2023.