On June 10, 2025, Xingu Rio Transmissora de Energia S/A – XRTE, a transmission company controlled by State Grid Brazil Holding, achieved another great feat: the modernization of its Special Protection System – SEP. This brings the Brazilian electrical system better performance in controlling the exchange of power between the Northeast and Southeast regions.
With the increase in wind and solar power generation in the Northeast and the growth in the volume of energy transmitted through the North-South and Northeast-Southeast corridors, the ONS identified the need to promote a new interconnection of the SEP associated with the Xingu Substation HVDC system with other regional protection systems. This modification will provide an increase in the energy exchange limit between the subsystems and will enable a reduction in the cut in renewable energy in the Northeast (known as “curtailment”).
Since this modification will be important during the upcoming dry season in the Northeast, a 60-day deadline was set for the implementation of these updates. Therefore, XRTE organized an integrated action plan with its internal areas and suppliers to make adjustments to the SEP Master Control within the required timeframe and without compromising the operation of the HVDC system. The steps included laboratory validation tests (RTDS at ONS), physical adjustments to panels, commissioning tests, and systemic tests with other agents in the sector.
The entire process was completed within the established deadline, ensuring gains to the protection system and contributing to the optimization of the Brazilian electrical energy system.
